17,163 results on '"HETEROGENEOUS CATALYSTS"'
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2. Recyclable Ni(II), Cu(II), and Co(II) complexes containing Schiff base immobilized on nanosilica as catalysts in oxidation of hydrocarbons
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Parada, J., Atria, A.M., Avilés, C., Mendoza, J., Basualto, C., Parra-Melipan, S., Zúñiga, C., and Aguirre, P.
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- 2024
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3. Nickel-promoted ruthenium nanocatalysts for controllable hydrogen production from NH3BH3 hydrolysis
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Cao, Yuyang, Yang, Shilong, Liu, Pu, Zhu, Qianqian, and Zheng, Xiucheng
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- 2025
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4. Achieving carbon neutrality through conversion of CO2 to cyclic carbonates using bifunctional benzimidazolium-based pyridine hypercrosslinked polymers
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Shu, You, Yang, Zhi-Yong, Pan, Wen-Kai, Xiang, De-Xuan, Wu, Jing-Gao, Gao, Lai-Hao, Jiao, Xu, He, Hong, Zhang, Zai-Xing, and Chen, Gui
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- 2025
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5. Oligomerization of ethylene to linear α-olefins catalyzed by Versailles/Santa Barbara-1 with LiAlH4
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Wang, Cong, Li, Gang, Huang, Zheng, and Peng, Anfeng
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- 2025
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6. Enhanced PMS activation through CuMo2S3 chalcogenide: Crucial role of MoXSX in restoring the Cu active sites of catalyst for pollutants removal
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Huang, Qiao, Shahzad, Ajmal, Ali, Jawad, Chen, Yanan, Ma, Haiqing, Wang, Zhao, Yang, Guang, and Xing, Futang
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- 2025
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7. Bis-imidazolium Pd(0) based supported catalyst for the selective dehydrogenation of formic acid
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Holakooei, Parvin, Valentini, Federica, Campana, Filippo, and Vaccaro, Luigi
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- 2024
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8. Biodiesel synthesis using spent FCC catalyst and CaO from a mixture of sunflower oil and oleic acid
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Vishnulal, K.S., Ramadesigan, Venkatasailanathan, and Seethamraju, Srinivas
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- 2024
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9. Fluorine-doped CoFe2O4/MoS2 for efficient Fenton catalysis at minimal oxidant dosage
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Yu, Haoran, Chu, Longgang, Gu, Cheng, and Xing, Mingyang
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- 2025
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10. TiO2/C coated Co3O4 nanocages for peroxymonosulfate activation towards efficient degradation of organic pollutants
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Klu, Prosper Kwame, Zhang, Hao, Nasir Khan, Muhammad Abdul, Wang, Chaohai, Qi, Junwen, Sun, Xiuyun, and Li, Jiansheng
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- 2022
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11. Metal-support spin orders: Crucial effect on electrocatalytic oxygen reduction.
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Chen, Yi-jie, Wen, Jun, Luo, Zhi-rui, Sun, Fu-Li, Chen, Wen-xian, and Zhuang, Gui-lin
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PHASE transitions , *METALLIC bonds , *HETEROGENEOUS catalysts , *CATALYST supports , *MAGNETIC anisotropy , *OXYGEN reduction - Abstract
Magnetic property (e.g. spin order) of support is of great importance in the rational design of heterogeneous catalysts. Herein, we have taken the Ni-supported ferromagnetic (FM) CrBr3 support (Nix/CrBr3) to thoroughly investigate the effect of spin-order on electrocatalytic oxygen reduction reaction (ORR) via spin-polarized density functional theory calculations. Specifically, Ni loading induces anti-FM coupling in Ni–Cr, leading to a transition from FM-to-ferrimagnetic (FIM) properties, while Ni–Ni metallic bonds create a robust FM direct exchange, benefiting the improvement of the phase transition temperature. Interestingly, with the increase in Ni loading, the easy magnetic axis changes from out-of-plane (2D-Heisenberg) to in-plane (2D-XY). The adsorption properties of Nix/CrBr3, involving O2 adsorption energy and configuration, are not governed by the d-band center but strongly correlate with magnetic anisotropy. It is noteworthy that the applied potential and electrolyte acidity triggers spin-order transition phenomena during the ORR and induces the catalytic pathway change from 4e− ORR to 2e− ORR with the excellent onset potential of 0.93 V/reversible hydrogen electrode, comparable to the existing most excellent noble-metal catalysts. Generally, these findings offer new avenues to understand and design heterogeneous catalysts with magnetic support. [ABSTRACT FROM AUTHOR] more...
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- 2024
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12. Toward efficient heterogeneous catalysts for in-situ hydrodeoxygenation of biomass
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Xu, Hao, Ju, Ji, and Li, Hao
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- 2022
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13. A six-membered N-heterocyclic polyionic liquids with palladium nanoparticles as a heterogeneous catalyst for the multicomponent one-pot reaction of carbon dioxide.
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Liang, Ying, Wang, Qing, Shen, Xiao-Xiao, Yang, Jin-Ying, Chen, Pei-Bo, Fang, Ping, and Pan, Ying-Ming
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HETEROGENEOUS catalysts , *ALKYL compounds , *POLYMERIZED ionic liquids , *ALKYL group , *CARBON dioxide - Abstract
[Display omitted] A series of heterogeneous catalysts, designated as POP- n -Pd (where n = 1, 2, 3, or 4), were synthesized by polymerizing a six-membered N -heterocyclic compound with an alkyl substituted group monomer (S1), using divinylbenzene (DVB) as crosslinkers. This process was followed by the incorporation of palladium (Pd) nanoparticles. The impact of the substituted group and the S1 :DVB ratio in the catalysts, together with the reaction conditions, was investigated to assess their influence on the catalytic performance in converting propylamine, carbon dioxide (CO 2) and 4-iodoanisole to oxazolidinones. The POP-1-Pd catalyst, featuring a methyl substituted group and a S1 :DVB ratio of 1:4, exhibited remarkable efficiency, resulting in an excellent yield of 96 % under room temperature and ambient pressure conditions. Furthermore, it has demonstrated wide applicability across a variety of substrates and in the treatment of lime kiln exhaust gas. Additionally, POP-1-Pd can be used in a gram-scale reaction and maintains its performance after six recycles, with no significant decline in yield. The possible catalytic mechanism is proposed as follows: the catalyst's pores adsorb both CO 2 and substrates, creating a high concentration reactant enrichment microenvironment. This facilitates the activation of both CO 2 and substrates by the imidazole moiety and Pd nanoparticles in the catalyst, thereby generating oxazolidinones. [ABSTRACT FROM AUTHOR] more...
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- 2025
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14. Efficient hydrogen production from formic acid dehydrogenation over ultrasmall PdIr nanoparticles on amine-functionalized yolk-shell mesoporous silica.
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Chai, Hao, Hu, Jinsong, Zhang, Rongmei, Feng, Youcheng, Li, Haidong, Liu, Zhentao, Zhou, Chunhui, and Wang, Xilong
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KINETIC isotope effects , *CATALYTIC activity , *FORMIC acid , *HYDROGEN production , *POLAR effects (Chemistry) , *HETEROGENEOUS catalysts - Abstract
[Display omitted] • Novel yolk-shell Pd 4 Ir 1 /YSMSNs-NH 2 catalyst with highly dispersed PdIr alloy NPs was prepared. • The radially oriented mesoporous channels of Pd 4 Ir 1 /YSMSNs-NH 2 catalyst can promote mass transfer and increase accessibility. • The amine groups on the YSMSNs-NH 2 support can improve the dispersion and reduce the particle size of the PdIr active phases. • The ultrasmall size (1.4 nm) and high dispersion of PdIr alloy NPs could expose more catalytic active sites. • The Pd 4 Ir 1 /YSMSNs-NH 2 catalyst exhibits an initial TOF value of 5818 h−1 at 50 °C, with 100 % FA conversion and H 2 selectivity. Developing heterogeneous catalysts with exceptional catalytic activity over formic acid (HCOOH, FA) dehydrogenation is imperative to employ FA as an effective hydrogen (H 2) carrier. In this work, ultrasmall (1.4 nm) and well-dispersed PdIr nanoparticles (NPs) immobilized on amine-functionalized yolk-shell mesoporous silica nanospheres (YSMSNs) with radially oriented mesoporous channels have been synthesized by a co-reduction strategy. The optimized catalyst Pd 4 Ir 1 /YSMSNs-NH 2 (Pd/Ir molar ratio = 4:1) exhibited a remarkable turnover frequency (TOF) of 5818 h−1 and remarkable stability at 50 °C with the addition of sodium formate (SF), resulting in complete FA conversion and H 2 selectivity, exceeding most of the solid heterogeneous catalysts in previous reports under similar circumstances. Kinetic isotope effect (KIE) exploration indicates the cleavage of the C H bond is regarded as the rate-determining step (RDS) during the FA dehydrogenation process. Such excellent catalytic properties arise from the ultrafine and well-dispersed PdIr NPs supported on the nanosphere support YSMSNs-NH 2 , the electronic synergistic effect of PdIr alloy NPs, and the strong metal-support interaction (MSI) effect between the introduced PdIr NPs and YSMSNs-NH 2 support. This work offers a new paradigm for exploiting the highly effective silica-supported Pd-based heterogeneous catalysts over the dehydrogenation of FA. [ABSTRACT FROM AUTHOR] more...
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- 2025
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15. 0D–2D multifunctional bimetallic MOF derivative-MXene heterojunction for high areal capacity lithium-sulfur batteries.
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Wang, Jinxin, Zhang, Yongzheng, Chen, Zixin, Zhou, Zhiqiang, Wang, Jitong, Ma, Cheng, Qiao, Wenming, Xu, Zhi, and Ling, Licheng
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LITHIUM sulfur batteries , *ANCHORING effect , *LITHIUM ions , *BIMETALLIC catalysts , *CATALYST structure , *HETEROGENEOUS catalysts - Abstract
Designed an OD–2D bimetallic heterostructure based on MXene substrate (FeCo@Ti 3 C 2). The advantage of 2D structure is that it enhances the rapid diffusion and electronic conduction of lithium ions, enabling effective storage of sulfur substances and achieving the re reaction of polysulfides; The bimetallic 0D structure exhibits an efficient anchoring effect on polysulfides, effectively alleviating shuttle effects. And use it as a diaphragm coating to improve the stability of lithium sulfur batteries at high rates (703 mAh g−1 at 4 C at room temperature and 555 mAh g−1 at 2 C at 0 °C) and excellent capacity performance under high loads (5.5 mAh cm−2 after 100 cycles at a high sulfur content of 8.2 mg cm−2). [Display omitted] Lithium-sulfur (Li-S) batteries have attracted much attention due to their high specific capacity. However, at high loads and rates, the polysulfides conversion rate and ion transport of batteries are slow, limiting their commercialization. This work reports zero-dimensional (0D) bimetallic MOF derivatives grown in situ on two-dimensional (2D) MXene by electrostatic adsorption (FeCo@Ti 3 C 2). The 0D bimetallic structure effectively avoids the stacking of MXene while providing a dual catalytic site for polysulfides. The 2D structure of MXene also provides a large number of pathways for the rapid diffusion of lithium ions. This 0D–2D heterostructured heterogeneous catalyst with bimetallic synergistic active sites efficiently immobilizes and catalyzes polysulfides, providing a fast charge transfer pathway for the electrochemical reaction of lithium polysulfides. The Li-S battery with this multifunctional 0D–2D heterojunction structure catalyst has outstanding high rate capacity (703 mAh g−1 at 4 C at room temperature and 555 mAh g−1 at 2 C at 0 °C), fascinating capacity at high load (5.5 mAh cm−2 after 100 cycles at a high sulfur content of 8.2 mg cm−2). The study provides new ideas for the commercialization of high-efficiency Li-S batteries. [ABSTRACT FROM AUTHOR] more...
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- 2025
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16. Regulating coordination environment in metal-organic Framework@Cuprous oxide Core-Shell catalyst for Promoting electrocatalytic oxygen evolution reaction.
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Wang, Hui, Wang, Zijian, Ma, Jin, Chen, Jian, Li, Hong, Hao, Weiju, Bi, Qingyuan, Xiao, Shuning, Fan, Jinchen, and Li, Guisheng
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OXYGEN evolution reactions , *HETEROGENEOUS catalysts , *CUPROUS oxide , *STRUCTURAL stability , *CHARGE transfer , *HYDROGEN evolution reactions - Abstract
[Display omitted] As a kind of promising oxygen evolution reaction (OER) catalysts, metal–organic frameworks (MOF) are often constrained by their inherent poor electroconductivity and structural instability. In this study, we developed a mono-dispersed zeolitic imidazolate framework-67@cuprous oxide (ZIF-67@Cu 2 O) core–shell catalyst via in-situ growth method for highly efficient alkaline OER. The ZIF-67@Cu 2 O shows an excellent OER activity with a low overpotential of 254 mV at 10 mA cm−2 and Tafel slope of 87.9 mV·dec−1 in 1.0 M KOH. Furthermore, the ZIF-67@Cu 2 O also shows a high turnover frequency (TOF) of 0.166 s−1 at 1.60 V vs. RHE and long-term stability for 160 h at a high current density of 100 mA cm−2. The unique core–shell structure with the Cu 2 O core linked with ZIF-67 shell through interfacial di-oxygen bridge improves the structural stability, enhances the charge transfer, and provides more active sites. Moreover, the interfacial coordination structure was regulated from Co-N 4 to Co-N 2 O 2 which elevates the valence of Co sites and optimizes the adsorption free energy of oxygen-containing intermediates, thus improving the electrocatalytic OER performance. This work could propose the way for designing novel MOF-based nanomaterials and developing desirable and robust heterogeneous OER catalysts. [ABSTRACT FROM AUTHOR] more...
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- 2025
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17. In2O3/Bi2O3 interface induces ultra-stable carbon dioxide electroreduction on heterogeneous InBiOx catalyst.
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Chen, Xiaoyu, Feng, Shuoshuo, Yan, Jiaying, Zou, Yanhong, Wang, Linlin, Qiao, Jinli, and Liu, Yuyu
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CATALYST selectivity , *HETEROGENEOUS catalysts , *COMPOSITE materials , *CARBON dioxide , *STANDARD hydrogen electrode , *ELECTROLYTIC reduction - Abstract
InBiO 6 catalyst is employed for the electroreduction of CO 2. In 2 O 3 /Bi 2 O 3 interface effects exhibit low negative potential and high formate Faradaic efficiency. The study described presents an effective approach for developing high-performance CO 2 reduction electrocatalysts derived from metal-organic frameworks. [Display omitted] • InBiO 6 two-phase co-existing composites was designed for CO 2 electroreduction. • High FE formate (>80 %) in a wide potential window (−0.76 ∼ −1.26 V vs. RHE). • Long-term stability of 317h in H-type cell. • The introduction of Bi changes the electronic environment around In and activates the In sites. • DFT calculations reveal that the heterostructure benefit formate production. The electrochemical reduction of CO 2 (ERCO 2) has emerged as one of the most promising methods for achieving both renewable energy storage and CO 2 recovery. However, achieving both high selectivity and stability of catalysts remains a significant challenge. To address this challenge, this study investigated the selective synthesis of formate via ERCO 2 at the interface of In 2 O 3 and Bi 2 O 3 in the InBiO 6 composite material. Moreover, InBiO 6 was synthesized using indium-based metal–organic frameworks as precursor, which underwent continuous processing through ion exchange and thermal reduction. The results revealed that the formate Faradaic efficiency (FE formate) of InBiO 6 reached nearly 100 % at −0.86 V vs. reversible hydrogen electrode (RHE) and remained above 90 % after continuous 317-h electrolysis, which exceeded those of previously reported indium-based catalysts. Additionally, the InBiO 6 composite material exhibited an FE formate exceeding 80 % across a wide potential range of 500 mV from −0.76 to −1.26 V vs. RHE. Density-functional theory analysis confirmed that the heterogeneous interface of InBiO 6 played a role in achieving optimal free energies for *OCHO on its surface. Furthermore, the addition of Bi to the InBiO 6 matrix facilitated electron transfer and altered the electronic structure of In 2 O 3 , thereby enhancing the adsorption, decomposition, and formate production of *OCHO. [ABSTRACT FROM AUTHOR] more...
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- 2025
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18. Oxidative conversion of lignin into monophenolic compound catalyzed by NaOH–NaAlO2/γ-Al2O3 under mild conditions.
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Zhou, Yijie, Luo, Kehui, Wu, Zhenzhen, and Fan, Guozhi
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WHEAT straw , *HETEROGENEOUS catalysts , *CATALYTIC activity , *LIGNINS , *OXIDIZING agents , *LIGNANS - Abstract
A heterogeneous catalyst NaOH–NaAlO2/γ-Al2O3 was prepared by supporting NaOH and NaAlO2 on γ-Al2O3, and it was further employed for the oxidative degradation of lignin. The influence of the oxidant, the molar ratio of NaOH to NaAlO2, and calcination temperature of the supported catalyst on the catalytic activity were investigated. Air was found to be an effective oxidant for lignin conversion in the presence of heterogeneous catalyst. The total yield of monophenolic compounds (MPCs) from dealkaline lignin was 13.0 %, which was obtained by using NaOH–NaAlO2/γ-Al2O3 calcinated at 550 °C as the catalyst with 2:3 M ratio of NaOH to NaAlO2 at 170 °C for 2.5 h in air. Vanillin and syringaldehyde were found to be the main products, giving yields of 6.7 and 2.9 %, respectively. The conversion of lignin derived from wheat straw was also carried out under the identical conditions. Wheat straw lignin also displayed considerable conversion to MPCs in the presence of NaOH–NaAlO2/γ-Al2O3, and the total yield of MPCs at 12.3 % was obtained at 180 °C. NaOH–NaAlO2/γ-Al2O3 was recovered by filtration after the reaction and reused without further treatment, and 11.0 % total yield of MPCs was obtained after four cycles. [ABSTRACT FROM AUTHOR] more...
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- 2025
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19. Robust phosphine-based covalent-organic framework palladium catalysts for the highly efficient carbonylation coupling reaction.
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Yu, Benling, He, Liuqing, Wei, Shiyuan, Li, Jiawei, Wang, You, Zhong, Juan, Huang, Jianhan, and Liu, You-Nian
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COUPLING reactions (Chemistry) , *CONDENSATION reactions , *CARBONYLATION , *PALLADIUM catalysts , *HETEROGENEOUS catalysts - Abstract
The first vinyl-linked PPh3-based covalent-organic frameworks (Pd@TMBen-PPh3 and Pd@TMBen-4F-PPh3) were facilely constructed via direct three-component Knoevenagel condensation, which could serve as outstanding heterogeneous catalysts for the Pd-catalyzed carbonylation coupling reaction owing to the synergistic effect of the flexible PPh3-ligated Pd complexes and the rigid framework. [ABSTRACT FROM AUTHOR] more...
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- 2025
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20. Bifunctional chlorhexidine-based covalent organic polymers for CO2 capture and conversion without a co-catalyst.
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Zhang, Ruiying, Shen, Yue, Liu, Lin, and Han, Zhengbo
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HETEROGENEOUS catalysts , *LEWIS acids , *CARBON dioxide , *POLYMERS , *EPOXY compounds , *COBALT catalysts - Abstract
Two new cobalt/zinc-coordinated bifunctional covalent organic polymers (COP-Co and COP-Zn) based on chlorhexidine are prepared as heterogeneous catalysts for carbon dioxide (CO2) conversion. Due to the Cl− nucleophile and cobalt/zinc Lewis acid sites, COP-Co and COP-Zn can efficiently convert CO2 and epoxides into cyclic carbonates under mild conditions without a co-catalyst. [ABSTRACT FROM AUTHOR] more...
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- 2025
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21. Challenges and opportunities in catalytic hydrogenolysis of oxygenated plastics waste: polyesters, polycarbonates, and epoxy resins.
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Mitta, Harisekhar, Li, Lingfeng, Havaei, Mohammadhossein, Parida, Dambarudhar, Feghali, Elias, Elst, Kathy, Aerts, Annelore, Vanbroekhoven, Karolien, and Van Geem, Kevin M.
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CHEMICAL recycling , *HETEROGENEOUS catalysts , *WASTE minimization , *CATALYST supports , *ECONOMIC competition , *POLYESTERS - Abstract
This review comprehensively explores various homogeneous and heterogeneous catalytic systems for the hydrogenolysis of oxygenated plastic waste (OXPs), presenting an adaptable solution to plastic pollution and generating valuable feedstock. Research demonstrates enhanced hydrogenolysis efficiency with reduced energy consumption, yielding alcohols, alkanes, alkenes, and aromatics. The effectiveness of depolymerization and the product distribution are influenced by factors such as solvents, ligands, metals, catalyst support, and reaction conditions. Scaling up these processes remains challenging, highlighting the need for non-toxic, highly active catalysts. Promising homogeneous catalysts, such as Ru(triphos-Xyl), and heterogeneous catalysts, such as Ru/Nb2O5, show potential in OXP depolymerization but face cost-related scalability issues. Homogeneous catalysts encounter commercialization obstacles due to harsh reaction conditions and difficulties in product separation, whereas heterogeneous catalysts like Ru/Nb2O5 provide effectiveness and stability with easier product separation. Nonetheless, challenges in scaling up, cost reduction, and catalyst reusability persist. Achieving economic viability is crucial for the commercialization of OXP hydrogenolysis and the reduction of plastic waste. The review emphasizes the shortage of depolymerization facilities for polyesters like poly(ethylene terephthalate) (PET), poly(bisphenol A carbonate) (BPA-PC), and epoxy resins (EP). It addresses recycling process challenges, focusing on sorting and supply chain issues, and identifies specific difficulties in recycling BPA-PC, PET, and EP materials, proposing chemical recycling as a viable solution to improve economic competitiveness and environmental sustainability. [ABSTRACT FROM AUTHOR] more...
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- 2025
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22. Copper complex of phenylglycine-functionalized UiO-66-NH2: a chiral MOF catalyst for enantioselective Henry reaction.
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Rasolinia, Khadijeh, Arvinnezhad, Hamid, and Samadi, Saadi
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NITROALDOL reactions , *CATALYTIC activity , *LIGANDS (Chemistry) , *X-ray diffraction , *COPPER , *HETEROGENEOUS catalysts - Abstract
In this study, a Zr based MOF chiral catalyst was synthesized, characterized, and then examined in the enantioselective Henry reactions. The process involved the synthesis of UiO-66-NH2, followed by its functionalization with 2-chloroacetyl chloride. Subsequently, L -phenylglycine was immobilized on the functionalized MOF to prepare a chiral heterogeneous ligand. Finally, the prepared chiral ligand was complexed with Cu(CH3CN)4PF6 to obtain the chiral heterogeneous catalyst. All of the synthesized materials were characterized using various methods including FT-IR, XRD, SEM, EDX, elemental mapping, and BET/BJH analysis. Evaluation of the catalytic activity of the prepared chiral heterogeneous catalyst under different conditions demonstrated that the best results can be achieved under solvent free green conditions at room temperature, producing excellent yields and low to moderate enantioselectivities. The heterogeneous catalyst was recovered and reused easily, maintaining activity over three consecutive cycles. [ABSTRACT FROM AUTHOR] more...
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- 2025
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23. Novel sustainable biodiesel production from low-grade oleic acid via esterification catalyzed by characterized crystalline ZrO2/Al2O3.
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Alkahlawy, Amal and Gaffer, Amany
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SUSTAINABILITY , *PHYSICAL & theoretical chemistry , *RENEWABLE energy sources , *X-ray photoelectron spectroscopy , *HETEROGENEOUS catalysts - Abstract
The depletion of fossil fuels and growing environmental concerns necessitate the exploration of renewable energy sources. Biodiesel, a promising alternative fuel derived from sustainable feedstock, has attracted considerable attention. This study investigates the catalytic esterification of oleic acid, a readily available fatty acid, with ethanol for biodiesel production using a novel heterogeneous catalyst, ZrO2/Al2O3. Crystalline ZrO2/Al2O3 was successfully synthesized and characterized using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, and Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption NH3-TPD to understand its structural and textural properties. The characterized ZrO2/Al2O3 was then employed to catalyze the esterification reaction. The influence of reaction parameters, including temperature, alcohol-to-oleic acid molar ratio, and catalyst loading, was systematically evaluated. Under optimal conditions (70 °C, 10:1 alcohol-to-oleic acid molar ratio, and 4 wt% catalyst loading), a remarkable 90.5% conversion of oleic acid to biodiesel was achieved. Furthermore, the catalyst exhibited reusability, demonstrating its potential for sustainable biodiesel production from low-grade oleic acid feedstock. [ABSTRACT FROM AUTHOR] more...
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- 2025
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24. Novel sustainable biodiesel production from low-grade oleic acid via esterification catalyzed by characterized crystalline ZrO2/Al2O3.
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Alkahlawy, Amal and Gaffer, Amany
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SUSTAINABILITY ,PHYSICAL & theoretical chemistry ,RENEWABLE energy sources ,X-ray photoelectron spectroscopy ,HETEROGENEOUS catalysts - Abstract
The depletion of fossil fuels and growing environmental concerns necessitate the exploration of renewable energy sources. Biodiesel, a promising alternative fuel derived from sustainable feedstock, has attracted considerable attention. This study investigates the catalytic esterification of oleic acid, a readily available fatty acid, with ethanol for biodiesel production using a novel heterogeneous catalyst, ZrO
2 /Al2 O3 . Crystalline ZrO2 /Al2O3 was successfully synthesized and characterized using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, and Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption NH3 -TPD to understand its structural and textural properties. The characterized ZrO2 /Al2 O3 was then employed to catalyze the esterification reaction. The influence of reaction parameters, including temperature, alcohol-to-oleic acid molar ratio, and catalyst loading, was systematically evaluated. Under optimal conditions (70 °C, 10:1 alcohol-to-oleic acid molar ratio, and 4 wt% catalyst loading), a remarkable 90.5% conversion of oleic acid to biodiesel was achieved. Furthermore, the catalyst exhibited reusability, demonstrating its potential for sustainable biodiesel production from low-grade oleic acid feedstock. [ABSTRACT FROM AUTHOR] more...- Published
- 2025
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25. Synergize Strong and Reactive Metal‐Support Interactions to Construct Sub‐2 nm Metal Phosphide Cluster for Enhanced Selective Hydrogenation Activities.
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Chen, Zemin, Li, Xinyu, Xu, Guangyue, Xiao, Tianci, Wang, Dechen, Wang, Chufei, Zhang, Kaihang, Li, Jiong, Pan, Yang, Qiao, Yan, and Zhang, Ying
- Abstract
Strong metal‐support interactions (SMSI) are crucial for stabilizing sub‐2 nm metal sites, e.g. single atom (M1) or cluster (Mn). However, further optimizing sub‐2 nm sites to break the activity–stability trade‐off due to excessive interactions remains significant challenges. Accordingly, for the first time, we propose synergizing SMSI with reactive metal‐support interactions (RMSI). Comprehensive characterization confirms that the SMSI stabilizes the metal and regulates the aggregation of Ni1 into Nin site within sub‐2 nm. Meanwhile, RMSI modulates Nin through sufficiently activating P in the support and eventually generates sub‐2 nm metal phosphide Ni2P cluster (Ni2Pn). The synergetic metal‐support interactions triggered the adaptive coordination and electronic structure optimization of Ni2Pn, leading to the desired substrate adsorption‐desorption kinetics. Consequently, the activity of Ni2Pn site greatly enhanced towards the selective hydrogenations of p‐chloronitrobenzene and alkynyl alcohol. The formation rates of target products are up to 20.2 and 3.0 times greater than that of Ni1 and Nin site, respectively. This work may open a new direction for metal‐support interactions and promote innovation and application of active sites below 2 nm. [ABSTRACT FROM AUTHOR] more...
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- 2025
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26. Fundamentals and Challenges of Ligand Modification in Heterogeneous Electrocatalysis.
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Kong, Xiangdong, Zhu, Jiangchen, Xu, Zifan, and Geng, Zhigang
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CLEAN energy , *HETEROGENEOUS catalysis , *LIGANDS (Chemistry) , *POLAR effects (Chemistry) , *CATALYST structure , *HETEROGENEOUS catalysts - Abstract
The development of efficient catalytic materials in the energy field could promote the structural transformation from traditional fossil fuels to sustainable energy. In heterogeneous catalytic reactions, ligand modification is an effective way to regulate both electronic and steric structures of catalytic sites, thus paving a prospective avenue to design the interfacial structures of heterogeneous catalysts for energy conversion. Although great achievements have been obtained for the study and applications of heterogeneous ligand‐modified catalysts, the systematical refinements of ligand modification strategies are still lacking. Here, we reviewed the ligand modification strategy from both the mechanistic and applicable scenarios by focusing on heterogeneous electrocatalysis. We elucidated the ligand‐modified catalysts in detail from the perspectives of basic concepts, preparation, regulation of physicochemical properties of catalytic sites, and applications in different electrocatalysis. Notably, we bridged the electrocatalytic performance with the electronic/steric effects induced by ligand modification to gain intrinsic structure‐performance relations. We also discussed the challenges and future perspectives of ligand modification strategies in heterogeneous catalysis. [ABSTRACT FROM AUTHOR] more...
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- 2025
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27. Manganese Carbodiimide (MnNCN): A New Heterogeneous Mn Catalyst for the Selective Synthesis of Nitriles from Alcohols.
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Liu, Xixi, Han, Bo, Wu, Chongbei, Zhou, Peng, Jia, Meilin, Zhu, Liangfang, and Zhang, Zehui
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SCISSION (Chemistry) , *OXIDATIVE dehydrogenation , *AMMOXIDATION , *CATALYST synthesis , *HETEROGENEOUS catalysts - Abstract
Earth‐abundant manganese oxides (MnOx) were competitive candidates when screening catalysts for ammoxidation of alcohols into nitriles due to their redox property. However, over‐oxidation and possible acid‐catalyzed hydrolysis of nitriles into amides still limited the application of MnOx in nitrile synthesis. In this work, manganese carbodiimide (MnNCN) was first reported to be robust for the ammoxidation of alcohols into nitriles, avoiding over‐oxidation and the hydrolysis. Besides the high activity and selectivity, MnNCN demonstrated wide substrate scope including the ammoxidation of primary alcohols into nitriles, the oxidative C−C bonds cleavage and ammoxidation of secondary alcohols, phenyl substituted aliphatic alcohols, and diols into nitriles. Controlled experiments and DFT calculation results revealed that the excellent catalytic performance of MnNCN originated from its high ability in the activation of O2 molecules, and favorable oxidative dehydrogenation of C=N bonds in the aldimine intermediates (RCH=NH) into nitriles, inhibiting the competitive side reaction of the oxidation of aldehydes into carboxylic acids, followed to amide byproducts. Moreover, the hydrolysis of nitriles was also inhibited over MnNCN for its weak acidity as compared with MnOx. This study provided new insights into Mn‐catalyzed aerobic oxidations as a highly important complement to manganese oxides. [ABSTRACT FROM AUTHOR] more...
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- 2025
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28. The Swiss Army Knife of Electrodes: Pillar[6]arene‐Modified Electrodes for Molecular Electrocatalysis Over a Wide pH Range.
- Author
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Roithmeyer, Helena, Bühler, Jan, Blacque, Olivier, Tuncay, Isik, Moehl, Thomas, Invernizzi, Cristiano, Keller, Florian, Iannuzzi, Marcella, and Tilley, S. David
- Subjects
- *
INDIUM tin oxide , *HOST-guest chemistry , *BENZYL alcohol , *CATALYTIC activity , *RUTHENIUM compounds , *HETEROGENEOUS catalysts - Abstract
Molecularly‐modified electrode materials that maintain stability over a broad pH range are rare. Typically, each electrochemical transformation necessitates a specifically tuned system to achieve strong binding and high activity of the catalyst. Here, we report the functionalisation of mesoporous indium tin oxide (mITO) electrodes with the macrocyclic host molecule pillar[6]arene (PA[6]). These electrodes are stable within the pH range of 2.4–10.8 and can be equipped with electrochemically active ruthenium complexes through host–guest interactions to perform various oxidation reactions. Benzyl alcohol oxidation serves as a model reaction in acidic media, while ammonia oxidation is conducted to assess the systems performance under basic conditions. PA[6]‐modified electrodes demonstrate catalytic activity for both reactions when complexed to different guest molecules and can be reused by reabsorption of the catalyst after its degradation. Furthermore, the system can be employed to perform subsequent reactions in electrolyte with varying pH, enabling the same electrode to be utilised in multiple different electrocatalytic reactions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
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29. CoSe2@NiSe‐CoSe2 Heterojunction for Enhanced Electrocatalytic 5‐Hydroxymethylfurfural Oxidation Coupled with Hydrogen Evolution.
- Author
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Liu, Shuai, Cai, Wenting, Jin, Mengmeng, Zhang, Tongxue, Zhang, Zhiwei, Liu, Qingzhao, Liu, Xijun, Zhang, Xubin, and Wang, Fumin
- Subjects
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CHEMICAL synthesis , *HYDROGEN evolution reactions , *ACTIVATION energy , *HYDROGEN as fuel , *BIOMASS conversion , *HETEROGENEOUS catalysts - Abstract
Electrochemical 5‐hydroxymethylfurfural oxidation reaction (HMFOR) offers a promising approach to producing valuable chemicals and facilitating coupled H2 production. A significant challenge in the HMFOR lies in elucidating the interaction mechanisms between the active sites and 5‐hydroxymethylfurfural (HMF). However, the unpredictable reconstruction of active sites during the catalytic process complicates the understanding of these mechanisms. In this study, a novel heterojunction (CoSe2@NiSe‐CoSe2/NF) is synthesized using a straightforward hydrothermal method combined with classical selenization. This heterojunction demonstrates exceptional electrocatalytic performance for direct HMF oxidation, achieving a Faradaic efficiency of 2,5‐furanedicarboxylic acid (FDCA) up to 97.9%. Notably, it requires only 1.29 V versus RHE to achieve a current density of 10 mA cm−2 for the HMFOR‐assisted hydrogen evolution reaction (HER). The high activity of the heterojunction primarily arises from interfacial electron redistribution. Specifically, Co modulates the band structure of Ni, with Se serving as the intermediary. This modulation increases the adsorption energy of HMF and reduces the energy barrier of the rate‐determining step in HMFOR. This research not only achieves the selective synthesis of high‐value chemicals but also provides a comprehensive analysis of the structure‐performance relationship of the catalyst, offering a new pathway for the development of efficient heterogeneous catalysts. [ABSTRACT FROM AUTHOR] more...
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- 2025
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30. Innovative Mn2Sb2O7 Nanocatalysts: Effective Generation of 2‐Amino‐4H‐Chromenes Through Strategic Metal Doping.
- Author
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Jahangiri, Sasan, Poursattar Marjani, Ahmad, and Kafi‐Ahmadi, Leila
- Subjects
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FOURIER transform infrared spectroscopy , *HETEROGENEOUS catalysts , *NANOPARTICLES , *TRANSMISSION electron microscopy , *TURNOVER frequency (Catalysis) - Abstract
This study focuses on the synthesis and characterization of Mn₂Sb₂O₇ and MnSb₂O₆ nanocatalysts, which were analyzed using Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), Brunauer‐Emmet‐Teller (BET) analysis, scanning electron microscopy with energy dispersive X‐ray (SEM‐EDS), and transmission electron microscopy (TEM). The results confirm that the catalysts have similar chemical compositions and structures, with small amounts of vanadium (V) or iron (Fe) dopants evenly distributed throughout the material. These nanocatalysts demonstrated high efficiency in the one‐pot synthesis of 2‐amino‐4H‐chromenes from malononitrile, dimedone, and aryl aldehydes, achieving yields of 66–90% under optimal conditions using 10 mg of catalyst in ethanol at room temperature. Due to their amphoteric nature, the catalysts enable reactions via acid‐mediated or base‐mediated Hann‐Lapworth mechanisms. Under optimal conditions, the catalysts exhibited turnover numbers (TON) ranging from 1.8 to 3.6 and turnover frequencies (TOF) between 0.0005 and 0.0009 s⁻¹. Moreover, the catalysts can be recovered and reused without losing activity, making them valuable for sustainable chemical synthesis applications. [ABSTRACT FROM AUTHOR] more...
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- 2025
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31. Green Chemical Synthesis of Cube‐Shaped CuFe2O4 Nanoparticles for Use as Magnetically Retrievable Catalysts in A3 Coupling Reactions.
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Kalita, Babul, Iraqui, Saddam, Sarmah, Mrinmoy J., Chatterjee, Souvik, and Rashid, Md. Harunar
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COUPLING reactions (Chemistry) , *ETHYNYL benzene , *HETEROGENEOUS catalysts , *CATALYTIC activity , *LANTANA camara - Abstract
A3 coupling reaction is a multicomponent reaction (MCR) involving aryl aldehydes, phenyl acetylenes and amines to synthesize a variety of biologically active propargylamine derivatives. Herein, we report the preparation of cube‐shaped CuFe2O4 nanoparticles (NPs) via the hydrothermal method in the presence of Lantana camara flower (LCF) extract to use them as catalysts to synthesize propargylamine derivatives. X‐ray diffraction study confirms the formation of CuFe2O4 NPs with cubic spinel structures. In the presence of LCF extract, cube‐shaped CuFe2O4 NPs are formed predominantly irrespective of the type of alkali used as the hydrolyzing agent. However, a mixture of nearly spherical and cube‐shaped particles has been formed in the absence of additives. The synthesized CuFe2O4 NPs exhibit superparamagnetic behaviour and are magnetically ordered. The synthesized cube‐shaped CuFe2O4 NPs exhibit excellent catalytic activity in the A3 coupling reaction between benzaldehyde, piperidine and phenylacetylene to give propargylamine with a yield of 90% under the optimum conditions. The catalyst is highly stable and magnetically retrievable facilitating reusability for up to five cycles without considerable loss of catalytic activity. The protocol is suitable for the synthesis of a diverse range of propargylamine derivatives with moderate to excellent yield. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
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32. A Size‐Matched Composite (CTA)3PW4@UiO‐67 for the Ultra‐Deep Desulfurization of Simulated Diesel: Design, Performance, and Reusability.
- Author
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Gao, Yan, Zhao, Shumin, Huang, Jingwen, Han, Tao, and Zhao, Jianshe
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CHEMICAL processes , *HETEROGENEOUS catalysts , *DESULFURIZATION , *SINGLE molecules , *POLYOXOMETALATES - Abstract
Venturello‐structured polyoxometalates (POMs) are effective homogeneous catalysts and confining POMs to size‐matched metal‐organic frameworks (MOFs) as heterogeneous catalyst is an effective way to improve their practical application. The appropriate pore and narrow window of pristine UiO‐67 can not only enclose POMs in single molecule but also limit their leaching and can provide a suitable platform for the oxidation of most sulfur‐containing organic compound. The composite (CTA)3PW4@UiO‐67 was prepared by a facile in situ synthesis method, characterized by a variety of means and tested for desulfurization of multicomponent simulated diesel. The results prove that the active component (CTA)3PW4 is effectively encapsulated, and the composite (CTA)3PW4@UiO‐67 show remarkable desulfurization activity and excellent reusability. In addition, the kinetics and possible mechanism of the reaction were investigated. This work opens up a new idea for the design of "host‐guest adapted" catalyst suitable for fuel desulfurization technology. [ABSTRACT FROM AUTHOR] more...
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- 2025
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33. A Chemically Robust 2D Ni‐MOF as an Efficient Heterogeneous Catalyst for One‐Pot Synthesis of Therapeutic and Bioactive 2‐Amino‐3‐Cyano‐4H‐Pyran Derivatives.
- Author
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Mondal, Supriya, Pramanik, Bikram, Sahoo, Rupam, and Das, Madhab C.
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CHEMICAL stability ,HETEROGENEOUS catalysts ,CONDENSATION reactions ,CATALYST synthesis ,WASTE recycling ,PYRAN derivatives - Abstract
Despite possessing numerous catalytic advantages of MOFs, developing 2D frameworks having excellent chemical stability along with new catalytic properties remains a grand challenge. Herein, by employing a mixed ligand synthetic approach, we have constructed a 2D Ni‐MOF, IITKGP‐52, which exhibits excellent framework robustness in open air, water, as well as over a wide range of aqueous pH solutions (2–12). Benefitting from its robustness and abundant Lewis acidic open metal sites (OMSs), IITKGP‐52 is explored in catalyzing the heterogeneous three‐component condensation reaction for the tandem synthesis of bioactive 2‐amino‐3‐cyano‐4H‐pyran derivatives with low catalytic loading, greater compatibility for a wide range of substrates, excellent recyclability and superior catalytic efficiency than the previously employed homo and heterogeneous systems. IITKGP‐52inaugurates the employment of MOF‐based catalysts for one‐pot synthesis of therapeutic and bioactive 2‐amino‐3‐cyano‐4H‐pyran derivatives. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
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34. Pd‐Imidate@Sba‐15: A Multifunctional Heterogeneous Catalyst for the Aqueous Room Temperature Hydrogenation of Co2 to Formic Acid.
- Author
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Martín, Nuria, Porcar, Raúl, Serrano, José L., Pérez, José, Lozano, Pedro, Cirujano, Francisco G., and García‐Verdugo, Eduardo
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HETEROGENEOUS catalysis ,FORMIC acid ,HETEROGENEOUS catalysts ,CATALYSTS recycling ,CARBON dioxide - Abstract
The incorporation of hydrophilic and basic sites from phosphotriazaadamantane and saccharine in a water‐soluble Pd complex and the subsequent confinement into mesoporous silica support increases the activity and stability of the palladium catalytic species for the room‐temperature aqueous hydrogenation of either bicarbonate or CO2 into formic acid. The use of low Pd loadings (<0.1 mmolPd g−1) of the well‐dispersed complex on SBA‐15 mesoporous silica allows performing the reaction under room temperature, and aqueous conditions, exhibiting TON of ca. 40–100, for the CO2 or bicarbonate hydrogenation, respectively, which is one order of magnitude higher than the homogeneous case, allowing the easy isolation and recycling of the solid catalyst. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
- Full Text
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35. Sustainable Production of Biofuels from Biomass Feedstocks Using Modified Montmorillonite Catalysts.
- Author
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Ban, Lin, Wu, Deyu, Sun, Dalin, Zhou, Heng, Wang, Hao, Zhang, Heng, Charles Xu, Chunbao, and Yang, Song
- Subjects
SUSTAINABILITY ,MONTMORILLONITE catalysts ,FOSSIL fuels ,HETEROGENEOUS catalysis ,HETEROGENEOUS catalysts - Abstract
The rampant exploitation of fossil fuels has led to the significant energy scarcity and environmental disruption, affecting the sound momentum of development and progress of human civilization. To build a closed‐loop anthropogenic carbon cycle, development of biofuels employing sustainable biomass feedstocks stands at the forefront of advancing carbon neutrality, yet its widespread adoption is mainly hampered by the high production costs. Montmorillonite, however, has garnered considerable attention serving as an efficient heterogeneous catalyst of ideal economic feasibility for biofuel production, primarily due to its affordability, accessibility, stability, and excellent plasticity. Up to now, nevertheless, it has merely received finite concerns and interests in production of various biofuels using montmorillonite‐based catalysts. There is no timely and comprehensive review that addresses this latest relevant progress. This review fills the gap by providing a systematically review and summary in controllable synthesis, performance enhancement, and applications related to different kinds of biofuels including biodiesel, biohydrogenated diesel, levulinate, γ‐valerolactone, 5‐ethoxymethylfurfural, gaseous biofuels (CO, H2), and cycloalkane, by using montmorillonite catalysts and its modified forms. Particularly, this review critically depicts the design strategies for montmorillonite, illustrates the relevant reaction mechanisms, and assesses their economic viability, realizing sustainable biofuels production via efficient biomass valorization. Overall, this may offer valuable insights into cost‐effective biofuel production and proposes strategic recommendations for advancement of montmorillonite applications and future biofuel development. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
- Full Text
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36. Heteropolyacids combined with Y zeolite as superior solid acid catalysts to accelerate lactic acid esterification.
- Author
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Quan, Cui, Zhou, Yingying, Chu, Hua, Fan, Xiaolei, and Gao, Ningbo
- Subjects
ZEOLITE Y ,PHOSPHOTUNGSTIC acids ,LACTIC acid ,HETEROGENEOUS catalysts ,SCANNING electron microscopy ,ACID catalysts ,BIODEGRADABLE plastics - Abstract
BACKGROUND: Ethyl lactate produced via esterification between lactic acid and ethanol can be used in plastics, polymers and food industries and renowned for its biodegradability and low toxicity. However, lactic acid self‐catalyzed esterification presents a slow reaction process, and acid catalysts are needed to improve the catalysis. Homogeneous acid catalysts like H2SO4 are corrosive, as well as being difficult to be seperated from the reaction media; therefore, advanced heterogeneous catalysts are more ideal. In this study, two kinds of heteropolyacid–zeolite catalysts, involving loading silicotungstic acid and phosphotungstic acid onto Y zeolite, were synthesized, characterized using X‐ray diffraction, NH3 temperature‐programmed desorption and scanning electron microscopy and analyzed for their catalytic efficiency in the catalytic esterfication. RESULTS: Results showed that the Keggin structures of heteropolyacids were retained during the preparation process and strong acid sites of Y zeolite were enriched, which made the main contribution to the esterification of lactic acid and ethanol. Furthermore, the initial‐stage reaction rate of esterification was significantly enhanced. During the first hour of esterification, the conversion of lactic acid increased from 18% to 65%. Exp Dec1 index model was employed to determine the activation energies of 60HSiW‐Y and 60HPW‐Y, which exhibit values of 29.3 and 28.2 kJ mol−1, respectively. CONCLUSION: This study indicates that Keggin structures of heteropolyacids play a key role in the esterification and heteropolyacid–zeolite catalysts can effectively catalyze the esterification. Meanwhile, the results of the kinetic experiments can be of reference significance for large‐scale industrial processes involving esterification. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
- Full Text
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37. Development of Zn doping Fe‐Pd bifunctional mesh‐type catalyst for heterogeneous electro‐Fenton system.
- Author
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Zhang, Wenwen, Xie, Wenbin, Ma, Tianen, and Zhang, Qi
- Subjects
CHEMICAL kinetics ,HETEROGENEOUS catalysts ,DENSITY functional theory ,ACTIVATION energy ,PHENOL - Abstract
The Fe‐Pd bifunctional heterogeneous electro‐Fenton catalyst is an attractive option for the degradation of phenol wastewater. However, the catalyst faces issues such as inadequate yield of H2O2 on the Pd species and poor durability. In this study, we developed a bifunctional Fe‐Pd catalyst with Zn embedded into a mesh‐type γ‐Al2O3/Al support (ZnxFePd/γ‐Al2O3/Al). The characterization results indicate that the addition of Zn can improve the dispersion of the Pd component on the catalyst surface and promote the crystallization of Fe3O4. Density functional theory calculations reveal that Zn doping reduces the activation energy of the rate‐controlled step and promotes the desorption of products and intermediates in H2O2 synthesis. The reaction kinetics model was proposed. Furtherly, a possible reaction mechanism was proposed to explain the phenol degradation pathways. The selected Zn1.4FePd/γ‐Al2O3/Al catalyst achieved a degradation rate of 98.8% for phenol. The degradation rate remained above 85% after seven cycles. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
- Full Text
- View/download PDF
38. A nanocellulose from sugarcane bagasse as a template for nickel oxide nanoparticles for removal of organic dyes from aqueous solution.
- Author
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Mohammed, Kedir Seid, Atlabachew, Minaleshewa, Abdu, Biniyam, and Desalew, Ali Ahmed
- Subjects
- *
PRECIPITATION (Chemistry) , *PHYSICAL & theoretical chemistry , *MALACHITE green , *ORGANIC dyes , *HETEROGENEOUS catalysts - Abstract
The aquatic ecosystem is negatively impacted by organic dye contamination, which is now one of the factors leading to environmental pollution. The present investigation involved the synthesis of nanocellulose (NC) and nanocellulose modified with NiO (NC/NiO) composite using acid hydrolysis and a one-step precipitation technique for NC and NiO, respectively. Malachite green (MG) dye was catalytically removed from an aqueous solution using the two products, which were mechanically homogenized. The produced materials were examined using different characterization techniques, like FTIR, BET, Uv-vis, XRD, SEM-EDX, and TGA. The characterization findings showed the homogeneous distribution of NiO on the NC. With MG dye serving as the model dye, an experiment was conducted to determine the catalyst's catalytic removal ability. The catalytic degradation experiments validated the significance of NiO and the high catalytic activities of the synthesized NC/NiO composite toward the breakdown of MG dye. The kinetic study of catalytic malachite green (MG) dye removal is well-described by the pseudo-first-order kinetic model. After five reuse cycles, high removal efficiency was noted, demonstrating the composite's remarkable stability and reusability. As a result, it was determined that the NC/NiO composite was a suitable catalyst for the degradation of a dye (MG) from the aqueous solution in the presence of H2O2, with an apparent rate constant, kapp, greater than 0.519 min−1 and a catalytic efficiency of material by 10 mg catalyst was higher than 99% within 11 min at 48℃. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
39. Photo-assisted uranium extraction based on heterogeneous catalysts.
- Author
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Yu, Kaifu, Zhou, Li, Wu, Linzhen, Dong, Changxue, Dong, Huanhuan, Lian, Jie, Yang, Xiaoyong, Ahuja, Rajeev, Chen, Tao, and Zhu, Wenkun
- Subjects
- *
HETEROGENEOUS catalysts , *URANIUM - Published
- 2024
- Full Text
- View/download PDF
40. Biofuel conversion through heterogeneous solid catalysts and carbon nanotubes by biological waste material with sheep fat oil.
- Author
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Sathish, T., Saravanan, R., Giri, Jayant, Shaikh, Shoyebmohamad F., Ubaidullah, Mohd, and Ağbulut, Ümit
- Subjects
- *
HETEROGENEOUS catalysts , *SUSTAINABILITY , *BIOMATERIALS , *CARBON nanotubes , *NANOPARTICLES - Abstract
Heterogeneous solid catalysts have been largely developed for biodiesel production, because of their strong hydrothermal stability, attractive acid-base properties, and efficient recovery/reusability. Hence, the catalyst from biological waste was an effective choice because of its lower emissions, and cost-effective method than other catalysts preparations. In this study, the biofuel was prepared by using sheep fat oil using different biological waste catalysts under various operating conditions. The catalyst was prepared by microalgae ash, and waste fruit waste ash through a pyrolysis reactor at 250 °C for 30 min. Furthermore, the CNT nanoparticles integrated with the catalyst during transesterification to enhance the biofuel conversion efficiency. The conversion process was performed under operating conditions of various catalyst loading (5 wt%, 10 wt%, and 15 wt%), various oil: methanol ratios (1:4, 1:6, 1:8, and 1:10), and reaction times of about (60 min, 120 min, 180 min, and 240 min). Based on the experimental results, the following conclusions were drawn. The resulting, peak operating conditions such as catalyst loading of 15 wt%, oil: methanol ratios of 1:6, and reaction time of 240 min recorded a higher biofuel conversion than other conditions. Furthermore, the CNT nanoparticle integration within catalysts for both MAC and WFA is about 59.8%, 63.5%, 62.3%, and 61.6%, 60.2%, and 58.7% at a condition of higher Catalyst loading (15 wt%), Oil: methanol molar ratio (1:4), and reaction time (240 min). • Sustainable biofuel production through Transesterification of sheep fat oil. • Catalysis via Waste-Derived Materials such as Waste Fruit Ash and microalgae ash. • Composite Heterogeneous Catalysts employed with carbon nanotubes. • Impact of Reaction time catalyst loading and molar ratio on Conversion efficiency. • Maximum Conversion efficiency observed at Maximum reaction time and catalyst loading. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
41. Facile hydrothermal synthesis of VO2 nanosheets as robust catalysts for liquid-phase selective oxidation of benzyl alcohol under atmospheric O2.
- Author
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Wang, Rui-Ming, Yang, Si-Yao, Wang, Fei, Xu, Jie, and Xue, Bing
- Subjects
- *
SUSTAINABLE chemistry , *BENZYL alcohol , *METAL catalysts , *CATALYTIC activity , *HYDROTHERMAL synthesis , *HETEROGENEOUS catalysts , *ALCOHOL oxidation - Abstract
The liquid-phase selective oxidation of benzyl alcohol is a sustainable route for the synthesis of benzaldehyde. Wherein, the exploration of heterogeneous and cheap metal oxide catalysts instead of noble metal catalysts is of interest in both practical implementation and green chemistry. Herein, vanadium dioxide (VO2) nanosheets were prepared via a one-step hydrothermal reduction of V2O5 by citric acid. The hydrothermal temperature and time played important roles in determining the crystalline structure, morphology, and distribution of V valences of VO2 materials. In the selective oxidation of benzyl alcohol by atmospheric O2, VO2 materials as heterogeneous catalysts showed catalytic activity. Based on XPS and O2-TPD analysis, the catalytically active sites were proposed as V4+ species. At a reaction temperature of 95 °C, the maximum yield of benzaldehyde was up to 91.6% after 6 h, and the VO2-140-5 catalyst can be recycled at least five times without any obvious loss in activity. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
42. Adsorption, oxidation, kinetic and thermodynamic studies of methyl orange by magnetic Fe3O4 NPs and their chitosan/alginate nanocomposites.
- Author
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Şahin, Muradiye, Arslan, Yasin, and Tomul, Fatma
- Subjects
- *
CHEMICAL kinetics , *ACTIVATION energy , *FERRIC oxide , *HETEROGENEOUS catalysts , *MAGNETIC nanoparticles - Abstract
Magnetic iron oxide (Fe3O4) nanoparticles, iron oxide chitosan (Fe3O4-CS) and iron oxide alginate (Fe3O4-AT) nanocomposite beads were synthesised using green synthesis method. They were used as both adsorbents for the adsorption of methyl orange (MO) dye from the wastewater and heterogeneous catalysts for the catalytic wet peroxidation (CWPO) of MO. While the dye removal was successfully performed with Fe3O4NPs, Fe3O4-CS and Fe3O4-AT in both adsorption studies and CWPO, the highest removal efficiency (99%) in the shortest time (8 min for adsorption, 20 min for CPWO) was obtained with Fe3O4-CS for MO removal. The adsorption experiments were performed with the batch techniques at different contact time, pH, initial dye concentration, temperature, amount of adsorbent and foreign ion effect parameters by Fe3O4-CS adsorbent. The equilibrium was quickly reached after 30 min at pH 3 and 298 K. Fitting equilibrium data to Langmuir, Temkin and Freundlich isotherms showed that Langmuir model was more suitable to describe MO adsorption with a maximum monolayer adsorption capacity of 132 mg/g at 298 K. The Experimental data were analysed using intra particle diffusion, pseudo-first-order and pseudo-second-order kinetic models and it was found that the adsorption kinetics followed a pseudo-second-order equation. Based on thermodynamic studies, adsorption process occurred as spontaneous and exothermic. The effects of the amount of catalyst, pH, temperature and H2O2 concentration were investigated to determine their catalytic activities for the decomposition of MO with CWPO technique. The reusability of Fe3O4-CS for both adsorption and CWPO techniques for MO removal was performed, and the adsorption and oxidation efficiency was found to be 97%. Moreover, the reaction kinetics was also investigated and the oxidation reaction was in good agreement with the pseudo-first order kinetic model. The activation energy (Ea) of the reaction was found to be 10.72 kJ/mol. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
43. Facile hydrothermal synthesis of VO2 nanosheets as robust catalysts for liquid-phase selective oxidation of benzyl alcohol under atmospheric O2.
- Author
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Wang, Rui-Ming, Yang, Si-Yao, Wang, Fei, Xu, Jie, and Xue, Bing
- Subjects
SUSTAINABLE chemistry ,BENZYL alcohol ,METAL catalysts ,CATALYTIC activity ,HYDROTHERMAL synthesis ,HETEROGENEOUS catalysts ,ALCOHOL oxidation - Abstract
The liquid-phase selective oxidation of benzyl alcohol is a sustainable route for the synthesis of benzaldehyde. Wherein, the exploration of heterogeneous and cheap metal oxide catalysts instead of noble metal catalysts is of interest in both practical implementation and green chemistry. Herein, vanadium dioxide (VO
2 ) nanosheets were prepared via a one-step hydrothermal reduction of V2 O5 by citric acid. The hydrothermal temperature and time played important roles in determining the crystalline structure, morphology, and distribution of V valences of VO2 materials. In the selective oxidation of benzyl alcohol by atmospheric O2 , VO2 materials as heterogeneous catalysts showed catalytic activity. Based on XPS and O2 -TPD analysis, the catalytically active sites were proposed as V4+ species. At a reaction temperature of 95 °C, the maximum yield of benzaldehyde was up to 91.6% after 6 h, and the VO2 -140-5 catalyst can be recycled at least five times without any obvious loss in activity. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
- Full Text
- View/download PDF
44. Heterogenization of Palladium Trimer and Nanoparticles Through Polymerization Boosted Catalytic Efficiencies in Recyclable Coupling and Reduction Reactions.
- Author
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Wang, Miaomiao, He, Zhixin, Chen, Meng, Fu, Fangyu, and Wang, Yanlan
- Subjects
- *
HETEROGENEOUS catalysts , *PALLADIUM catalysts , *COUPLING reactions (Chemistry) , *CATALYTIC activity , *CATALYTIC polymerization - Abstract
The development of heterogeneous palladium catalysts has shown continuous vitality in the field of catalysis and materials. In this work, we report one concise free radical polymerization approach to accomplish the aromatic palladium trimer functionalized polymers PSSy‐[Pd3]+ (2) and its derived palladium nanoparticles (3). Full characterizations could confirm the successful combination of cationic [Pd3]+ or nanoparticles with poly(p‐sulfonated styrene) skeleton. Compared to their monomeric tri‐palladium precursor (1) and common Pd(dba)2, Pd(PPh3)4, Pd(OAc)2, heterogeneous PSSy‐[Pd3]+ (2) shows much superior catalytic activities (0.15 mol %, TOF=1333.3 h−1) in the SMCC reaction. The identically ligated PdNPs (3) are formed in‐suit in the presence of NaBH4 and accomplish quantitative reduction of 4‐nitrophenol in just 320 s (0.50 mol %, TOF=2250 h−1). Moreover, these heterogeneous catalysts are reused for 5–6 times without significant loss of catalytic activity. Their superior catalytic ability is probably attributed to the synergistic effect of polymer entanglement and the tri‐palladium fragment. This work enlightens that the immobilization of palladium clusters or nanoparticles by polymerization could offer multiple advantages in stability, efficiency and recyclability for their involved catalyses and show far‐reaching future implications. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
45. Hydroquinone-treated Cu3(BTC)2: a mixed-valence Cu(I/II) MOF catalyst for efficient cycloadditions.
- Author
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Park, Sun Ho, Kim, Hye Mi, Díaz-Ramírez, Mariana L., Lee, Sunggi, and Jeong, Nak Cheon
- Subjects
- *
COPPER , *HETEROGENEOUS catalysts , *CATALYTIC activity , *ETHYNYL benzene , *HYDROQUINONE , *COPPER catalysts , *MIXED oxide catalysts - Abstract
We present mixed-valence Cu(I)1Cu(II)2(BTC)2 [henceforth Cu(I / II)-HKUST-1], post-synthetically prepared via the hydroquinone (H2Q) treatment of Cu(II)3(BTC)2 (also referred to as HKUST-1) and its subsequent catalytic activity. This Cu(I / II)-HKUST-1 exhibits exceptional structural integrity and superior catalytic performance in the copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction between phenylacetylene and benzyl azide. These findings highlight the potential of mixed-valence Cu-based MOFs as effective and sustainable heterogeneous catalysts for organic transformations, paving the way for future advancements in MOF-based catalysis. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
46. Carbonylation Reactions Using Single‐Atom Catalysts.
- Author
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Jurado, Lole, Posada‐Pérez, Sergio, and Axet, M. Rosa
- Subjects
- *
HETEROGENEOUS catalysts , *CARBONYLATION , *HYDROFORMYLATION , *METHYL ether , *CATALYSTS , *ETHANOL - Abstract
The development of highly efficient and selective catalysts for carbonylation reactions represents a significant challenge in catalysis. Single‐atom catalysts (SACs) have postulated as promising candidates able to combine the strengths of both homogeneous and heterogeneous catalysts. In this paper, we review recent advances in tailoring solid supports for SACs to enhance their catalytic performance in carbonylation reactions. We first discuss the effect of supports on the hydroformylation reaction catalysed by SACs, followed by recent advances for methanol, ethanol, and dimethyl ether carbonylation reactions, focusing on the design of halide‐free catalysts with improved activity and stability. Finally, oxidative carbonylation is discussed. Overall, this review highlights the importance of tailoring solid supports for SACs to achieve highly active and selective catalysts in carbonylation reactions, paving the way for future developments in sustainable catalysis. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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47. Rational Assembly of Three‐component Coordination Polymers as Heterogeneous Catalysts for CO2 Cycloaddition and Cyanosilylation Reactions.
- Author
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Huang, Jian‐Bo, Yin, Lin, Yue, Tian‐Cai, Wang, Lu‐Lu, and Wang, Duo‐Zhi
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HETEROGENEOUS catalysts , *HETEROGENEOUS catalysis , *RING formation (Chemistry) , *LEWIS bases , *CATALYTIC activity , *COORDINATION polymers - Abstract
Four new coordination polymers based on 5‐(((1H‐imidazol‐2‐yl)methyl)amino) isophthalic acid (H3L) and auxiliary ligands (1,10‐phenanthroline, 2,2′‐bipyridine, and 4,4′‐bipyridine), namely, {[Zn(HL)(phen)(H2O)] ⋅ 2H2O}n (CP 1), {[Ni(HL)(phen)(H2O)]}n (CP 2), {[Ni(HL)(2,2′‐bpy)(H2O)] ⋅ 2H2O}n (CP 3) and {[Cd(HL)(4,4′‐bpy)0.5(H2O)] ⋅ 2H2O}n (CP 4) were rationally assembled. Furthermore, these four CPs were screened as heterogeneous catalysts for CO2 cycloaddition and cyanosilylation reactions under mild conditions. The catalytic experiments showed that CP 1 had the better catalytic performance, excellent substrate tolerance and recyclability for the above two reactions. It is speculated that the excellent activity of CP 1 may be due to the open Lewis base site and the Lewis acidic characteristics of the zinc (II) center. After five cycles, the catalytic activities of CP 1 did not significantly decrease, and the structures remained unchanged. Therefore, the CP 1 was considered efficient and stable heterogeneous catalysts for above the two reactions. [ABSTRACT FROM AUTHOR] more...
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- 2024
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48. Production and testing of mahua oil–based biodiesel synthesized through heterogeneous catalyst using experimental and numerical method.
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Prajapati, Lawalesh Kumar, Tiwari, Chandrabhushan, Verma, Tikendra Nath, Dwivedi, Gaurav, and Paliwal, Deepak
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HETEROGENEOUS catalysts ,RESPONSE surfaces (Statistics) ,FREE fatty acids ,DIESEL motor exhaust gas ,DIESEL fuels ,METHYL formate - Abstract
A two-step treatment of mahua oil was conducted to synthesize mahua biodiesel using heterogeneous biomass-based catalyst derived from mahua shell. Mahua oil having higher free fatty acid (FFA) content (about 19%) was esterified to reduce the FFA content up to 1%. The esterification process was carried out using 200 mL mahua oil, 5:1 molar ratio (methanol:oil), and 2.25 weight% of H
2 SO4 at a temperature of 60 °C for 3 h. Post esterification, a set of 16 experiments were created using a Box–Behnken design (BBD)–based response surface methodology (RSM) approach to conduct the transesterification of the esterified oil. Molar ratio, catalyst loading, reaction temperature, and reaction time were the four input variables chosen for the design of experiments. The optimized conditions for maximum biodiesel yield (87.7%) were found to be 14.88 molar ratio, 3.578% catalyst loading, 69.7 °C reaction temperature, and 81.9 min reaction time. The Diesel RK engine simulation tool which was experimentally validated for baseline diesel fuel was used for numerical simulation of mahua biodiesel. The performance, combustion, and emission behavior of mahua biodiesel analyzed using numerical simulation presented the sustainability of mahua biodiesel as an alternate fuel. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
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49. Oxygen Vacancies Enrichment in Citric Acid‐Assisted Synthesis of Zirconia Supported Ni Catalyst for Highly Selective Hydrogenolysis of 5‐Hydroxymethylfurfural.
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Guo, Dongwen, Wang, Feng, Xu, Qiong, Yin, Dulin, and Liu, Xianxiang
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OXYGEN vacancy ,NICKEL catalysts ,CATALYST supports ,HETEROGENEOUS catalysts ,HYDROGENOLYSIS - Abstract
2, 5‐Dimethylfuran (DMF), which is a promising new‐generation liquid biofuel, has attracted widespread attention owing to the sustainability of biomass‐derived energy sources. In this study, a highly dispersed zirconia‐supported nickel catalyst (CA−Ni/ZrO2) was prepared via citric acid‐assisted wetness impregnation for the selective hydrogenolysis of 5‐hydroxymethylfurfural (HMF) to produce DMF. The characterization results confirmed the presence of Zr3+ species in the mesoporous CA−Ni/ZrO2 catalyst and the formation of oxygen vacancies during its preparation, which led to the formation of a large number of catalytically active sites for the adsorption and activation of the C=O/C−O groups. Under appropriate reaction parameters, an excellent DMF selectivity of 99.1 % and an HMF conversion of 98.4 % were achieved. A suitable kinetic model revealed that DMF was preferentially formed via the 2,5‐dihydroxymethylfuran intermediate route, although a 5‐methylfurfural route was also observed. Additionally, the interaction between Ni and ZrO2 significantly affected the stability of the catalyst. This study will provide guidelines for optimizing the catalytic conversion of furan derivatives over heterogeneous catalysts. [ABSTRACT FROM AUTHOR] more...
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- 2024
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50. One‐Pot Effective Approach to 2,5‐Diformylfuran From Carbohydrates Using MoS2‐Decorated Carbonaceous Sugarcane Bagasse.
- Author
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Hao Nguyen, Trinh, Dinh Le, Diep, Le Nguyen, Dao Anh, Liang, Chien‐Fu, Bich Phan, Ha, and Hoang Tran, Phuong
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ACID catalysts ,CATALYST supports ,HETEROGENEOUS catalysts ,RENEWABLE natural resources ,BIOMASS conversion - Abstract
Exploring the transformation of carbohydrates into valuable chemicals offers a promising and eco‐friendly method for utilizing renewable biomass resources. Developing a bi‐functional, sustainable heterogeneous catalyst is of utmost importance to attain a high level of selectivity for the desired product, 2,5‐diformylfuran (DFF), in this direct conversion process. In this study, we developed a highly effective catalytic system to convert diverse carbohydrates into DFF. Our approach involved utilizing a MoS2 catalyst supported by amorphous carbon derived from sulfonated sugarcane biomass. The MoS2@SBG‐SO3H composite was successfully synthesized using a facile and highly efficient method. The transformation of fructose into DFF achieved a significant yield of 70 % for 5 h at 160 °C using a one‐step and one‐pot reaction through dehydration and oxidation with oxygen. The oxidation of 5‐hydroxymethylfurfural (HMF) into DFF using MoS2@SBG‐SO3H was obtained at 94 % DFF within 5 h; the activation energy was 38.3 kJ. mol−1. The catalyst displayed convenient recovery and reusability. The direct synthesis of DFF from various carbohydrates, such as sucrose, glucose, maltose, and lactose, resulted in favorable yields. Our research provides a quick, green, and efficient process for preparing carbon‐based solid acid catalysts and DFF. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
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