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This study consists of the synthesis of sustainable heterogeneous catalysts comprising dilacunary phosphotungstate and different acidic supports (zeolite HY and hydrous zirconia) via the incipient wet impregnation method. The catalysts were characterized by various physicochemical techniques and evaluated for solvent-free cleaner synthesis of n-butyl levulinate, a promising biofuel additive, under mild conditions. By undertaking a detailed optimization study, an outstanding selectivity of n-butyl levulinate (≥93%), as well as exceptional turnover numbers (>1300), was achieved. The reaction kinetics and order were investigated for both catalytic systems, revealing adherence to a true chemical step. The effect of the support was studied to compare the activity of the catalysts. The selected best catalyst was regenerated and recycled for multiple runs. Its versatility was explored in the esterification of a range of bio-based molecules into various biofuel additives with remarkable selectivity. Interestingly, it achieved over 90% selectivity for a range of C1–C7 straight-chain alcohols, marking a significant accomplishment. A high-gravity approach and scale-up reactions were also explored to ensure the practical relevance of the findings, emphasizing the potential of the catalyst for broader application. [ABSTRACT FROM AUTHOR]

Energy consumption remains a significant challenge in the removal of recalcitrant pollutants through advanced oxidation processes. In this study, a core–shell structural catalyst with graphitic carbon, encapsulating Fe3C and Fe3N (FeNC@C), was synthesized via pyrolysis for norfloxacin (NOR) degradation without extra energy. And we investigated several key parameters that influence the degradation of NOR, including H2O2 concentration, FeNC@C dosage, initial pH, and co-existing ions. The FeNC@C exhibits a degradation efficiency of 90% and total organic carbon removal exceeding 47% with 60 min. Our findings provide evidence that ˙OH is the primary reactive species in the process of NOR degradation. Additionally, we also propose a rational reaction mechanism and identify potential degradation intermediates. This study will facilitate further exploration of the heterogeneous catalyst as a potential approach for energy-efficient antibiotic decomposition. [ABSTRACT FROM AUTHOR]

SnO2 was synthesized using precipitation method, hydrothermal method, and sol–gel combustion method. The catalysts were characterized using various physiochemical techniques like X-ray diffraction (XRD), N2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron microscopy (XPS), and CO2-temperature programmed desorption (CO2-TPD). The catalysts were mesoporous in nature, and it was seen that the catalysts synthesized from sol–gel method (SnO2 (S)) showed tetragonal morphology with high crystallinity. Moreover, SnO2 (S) possessed high basicity with medium basic strength. The catalysts were further used for the synthesis of dimethyl carbonate (DMC) using urea and methanol. The study demonstrates that SnO2 catalysts were found to be effective for the DMC synthesis through urea route. Effect of Reaction conditions were optimized, and SnO2 (S) was found to give 51.9% DMC yield at 170 °C, 7 hours of time, with 0.2 g of the catalyst. The catalyst was easily recovered and reused, and the structure of SnO2 was found to be intact after the reaction. [ABSTRACT FROM AUTHOR]

[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]

[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]

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]

Most of the materials studied as catalysts in the electro-Fenton system are variants of iron oxide or iron hydroxide. However, iron-based catalysts often exhibit weak catalytic capabilities under neutral and alkaline conditions. In this work, we synthesized three cobalt based bimetallic oxides, Co2CuOx, Co2AlOx, and Co2NiOx, using hydrothermal method and evaluated them as catalysts for the heterogeneous electro-Fenton system to remove 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and Methylisothiazolinone [2-methyl-4-isothiazolin-3-one] (MIT). Co2NiOx has the highest catalytic degradation activity for HEDP, and Co2CuOx has the best catalytic degradation effect for MIT. Based on characterization results of the catalysts, the reasons for the differences in the pollutant removal efficiency were analysed, and the optimal pH for the three cobalt based oxides to remove HEDP and MIT was investigated. The results showed that the optimal pH values of the three cobalt based bimetallic oxides are not only influenced by the second metal type, but also by the properties of pollutants. Therefore, suitable cobalt based catalysts can be selected based on the different properties of pollutants, or the composition of cobalt based catalysts can be adjusted to meet the different pH requirements of target wastewater. The three cobalt based bimetallic oxides exhibited good degradation of HEDP and MIT under neutral conditions, which to some extent solved the problem of narrow pH range in the practical application of the electro-Fenton process. [ABSTRACT FROM AUTHOR]

Selective hydrogenation has been employed extensively to produce value-added chemicals and fuels, greatly alleviating the problems of fossil resources and green synthesis. However, the design and synthesis of highly efficient catalysts, especially those that are inexpensive and abundant in the earth's crust, is still required for basic research and subsequent industrial applications. In recent years, many studies have revealed that the rational design and synthesis of heterogeneous catalysts can efficaciously improve the catalytic performance of hydrogenation reactions. However, the relationship between nonprecious metal catalysts and hydrogenation performance from the perspective of different catalytic systems still remains to be understood. In this review, we provide a comprehensive and systematic overview of the recent advances in the synthesis of nonprecious metal catalysts for heterogeneous selective hydrogenation reactions including thermocatalytic hydrogenation/transfer hydrogenation, photocatalytic hydrogenation and electrocatalytic reduction. In addition, we also aim to provide a clear picture of the recent design strategies and proposals for the nonprecious metal catalysed hydrogenation reactions. Finally, we discuss the current challenges and future research opportunities for the precise design and synthesis of nonprecious metal catalysts for selective hydrogenation reactions. [ABSTRACT FROM AUTHOR]

A mild and efficient continuous-flow catalytic process for the reductive alkylation of methanol by various linear, cyclic, saturated, and unsaturated aliphatic ketones has been developed. This reaction, conducted at 130 °C using a Pd/C cartridge (5 wt%) under 1 bar of hydrogen, yields secondary O-methyl ethers in high yields. This innovative continuous process offers a new route for the synthesis of CPME, as a versatile eco-friendly solvent. Starting from arylic ketones, the same process furnished the corresponding tolyl derivatives via a reductive alkylation/hydrogenolysis sequence. A mechanism is proposed to explain these results. [ABSTRACT FROM AUTHOR]

Heterogeneous structures with rich phase boundaries are attractive for surface-mediated catalyst applications. Therefore, a practical solution involves constructing heterogeneous materials to maximize the functionality of electrocatalysts. In this study, we assembled a transition metal-based manganese-ferro selenide heterostructure nanosheet, combined with boron-doped carbon quantum dots (B-CQDs) on a foam nickel self-supporting electrocatalyst, using a two-step pyrolysis method (B-CQDs/MnFeSe/NF). The interface between the MnSe and FeSe components of the heterogeneous catalyst modulates the electronic structure, facilitates enhanced charge transfer, and improves structural stability, thereby increasing the efficiency of electrocatalytic water splitting. Consequently, the B-CQDs/MnFeSe/NF heterostructure reduces the hydrogen evolution reaction (HER) overpotential to 89 mV and the oxygen evolution reaction (OER) overpotential to 197 mV. Moreover, this catalyst requires only 1.52 V for the water splitting voltage at a current density of 10 mA cm−2. This work provides new insights into enhancing the intrinsic activity of overall water-splitting systems with heterogeneous structures. The novel B-CQDs/MnFeSe/NF catalyst was prepared using the solvothermal method, exhibiting excellent catalytic activity and stability in the overall water splitting reaction. [Display omitted] • B-CQDs/MnFeSe/NF catalyst was prepared using two-step solvothermal method. • Synergies of MnSe and FeSe promote electron transfer to enhance HER/OER activity. • Heterogeneous structure offers more active sites and transport channels for HER/OER. • B-CQDs/MnFeSe/NF.||B-CQDs/MnFeSe/NF shows 1.52 V operating voltage at 10 mA cm−2. • The overall water splitting on B-CQDs/MnFeSe/NF is nearly 100% Faraday efficiency. [ABSTRACT FROM AUTHOR]

[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]

Herein, the performance of heterobimetallic clusters MOF-1213(Dy/Ni) for ethylene oligomerization reactions was investigated. At 30 °C and 40 bar, its average ethylene turnover frequency is approximately 160 000 h−1 (α-olefins selectivity above 80%), which was higher than the activity previously reported for most heterogeneous catalysts under similar conditions. [ABSTRACT FROM AUTHOR]

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]

Introducing advanced carbon nanomaterials can provide considerable developments in the field of heterogeneous catalysis. In this study, a novel magnetic biochar was prepared via carbonization of semi-parasite Loranthus europaeus plants (wood waste) and Fe3O4-nanoparticles as precursor. Magnetic biochar was subsequently coated with Cu(II) complex to obtain a cost-effective and biocompatible catalyst, i.e., magnetic biochar bis(thiourea) triazine copper (II) complex (MBC@BTT-Cu(II)). This nanocatalyst is capable of promoting C–O bond-forming processes, which allows the formation of phenols in the natural deep eutectic as environmentally, friendly media and neoteric green solvents for the first time. The structures and properties of MBC@BTT-Cu(II) were fully characterized using various physicochemical techniques such as SEM, EDS, TGA, XRD, VSM, BET, CHN, AAS, and elemental mapping analysis. Furthermore, the as-prepared catalyst can be easily separated magnetically for several consecutive runs and exhibits significant recyclability without incredibly losing its activities. [ABSTRACT FROM AUTHOR]

Dual active sites with synergistic valence state regulation under oxidizing and reducing conditions are essential for catalytic reactions with step-wise mechanisms to modulate the complex adsorption sites of reactant molecules on the surfaces of heterogeneous catalysts with maximized catalytic performances, but it has been rarely explored. In this work, uniformly dispersed CuCo alloy and CoO nanosheet composite catalysts with dual active sites are constructed, which shows huge boost in activity for catalyzing water-gas shift reaction (WGSR), with a record high reaction rate reaching 204.2 μmolCO gcat.−1 s−1 at 300 °C for Cu1Co9Ox amongst the reported Cu-based and Co-based catalysts. A synergistic mechanism is proposed that Coδ+ species can be easily reduced by CO adsorbed on Cu and Co0 can be oxidized by H2O. Systematic in situ characterization results reveal that the addition of Cu can regulate the redox properties of Co species and thus modulate the adsorption properties of catalysts. Particularly, doping of Cu0 sites weakens the affinity of the surface to CO or CO2 to a moderate level. Moreover, it also promotes the oxidation of *CO to *COOH and the desorption of the product CO2, reducing the carbon poisoning of the catalyst and thus increasing the reactivity. The results would provide guidance for the construction of novel heterogeneous catalyst with dual active sites and clarify its underlying reactivity enhancement mechanism induced by the tunning of valence state of metal centers for heterogeneous catalytic reactions. Constructing catalysts with dual active sites is crucial for optimizing adsorption sites and enhancing catalytic performance. Here, uniformly dispersed CuCo alloy and CoO nanosheet composite catalysts with dual active sites were developed, significantly boosting activity in the water-gas shift reaction. [ABSTRACT FROM AUTHOR]

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]

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]

In recent years, the catalytic oxidation of cheap and easily available alcohols to value-added carboxylic acids has attracted considerable interest. In this work, a post-synthetic modification strategy was employed to anchor Cu species to coordinate with the -NH2 in UiO-66-NH2(Ce), obtaining the catalyst Cu-UiO-66-NH2(Ce). The catalyst exhibited excellent performance for the direct oxidation of alcohols to carboxylic acids under mild reaction conditions without extra bases. The synthesized materials were characterized by XRD, SEM, XPS, BET, FT-IR, Raman and ICP-OES, the results show that Cu species were successfully anchored onto UiO-66-NH2(Ce) by the coordination with N atoms. Moreover, the coordination between Cu ions and N atoms as well as the unique structure of UiO-66-NH2(Ce) could provide uniformly catalytic active centers on heterogeneous catalyst, which are essential for the high catalytic performance of the catalyst. Furthermore, the recyclability of the catalyst was also investigated, which can be recovered and recycled for 10 times without significant loss of catalytic activity. This work provides an efficient and cost-effective approach to the direct oxidation of alcohols to carboxylic acids. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

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]

Heterogeneous catalysts for parahydrogen-induced polarization (HET-PHIP) would be useful for producing highly sensitive contrasting agents for magnetic resonance imaging (MRI) in the liquid phase, as they can be removed by simple filtration. Although homogeneous hydrogenation catalysts are highly efficient for PHIP, their sensitivity decreases when anchored on porous supports due to slow substrate diffusion to the active sites and rapid depolarization within the channels. To address this challenge, we explored 2D metal-organic layers (MOLs) as supports for active Rh complexes with diverse phosphine ligands and tunable hydrogenation activities, taking advantage of the accessible active sites and chemical adaptability of the MOLs. By adjusting the electronic properties of phosphines, TPP-MOL-Rh-dppb (TPP = tris(4-carboxylphenyl)phosphine), featuring a κ 2-connected di(phosphine) ligand, generated hyperpolarized styrene achieving an over-2400-fold signal enhancement and a polarization level of 20% for 1H in methanol- d 4 solution. The TPP-MOL-Rh-dppb effectively inherited the high efficiency and pairwise addition of its homogenous catalyst while maintaining the heterogeneity of MOLs. This work demonstrates the potential of 2D phosphine-functionalized MOLs as heterogeneous solid support for HET-PHIP. [ABSTRACT FROM AUTHOR]

Cupric oxide (CuO) nanorods and nanoparticles were successfully fabricated by hydrothermal route and characterized as a catalyst. Instruments such as XRD, FT-IR, SEM, TEM, HR-TEM, EDS, and the N2 adsorption–desorption isotherm were used to characterize products. The possible crystal growth mechanism of rod structure was suggested by altering hydrogen peroxide concentration, time and temperature. Emerson's method and the chemical oxygen demand (COD) test evaluated the catalytic degradation of phenol solution over as-prepared materials in an O2 air bubbling system. The reaction is first-order and is respected due to the reaction being raining with excess oxygen. The impact of pH, catalyst loading and mechanism of catalytic reaction were estimated. An over 98% phenol removal was achieved by CuO nanorods within 50 min, and the experimental values were well-matched with the linear fit model (R2 = 0.998), and the rate constant was found to be 6.89 × 10–2 min−1. The reaction goes through an initial period of adsorption and then moves to a higher activity and is more stable. Therefore, the as-prepared CuO nanorods can be employed as a potential catalyst substance for the degradation of phenol in the wastewater due to the exterior morphology, surface area, pore size, and miller-index of the crystals. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

[Display omitted] • Catalytic activity and mechanism affected by the distance between the dual atoms. • Synergistic effect in h-DACs breaking the scaling relationships. • h-DACs-3.21 with excellent ORR and OER catalytic activity. Dual-atom catalysts with heteronuclear active sites (h-DACs) have better potential in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) than the recognized single atom catalysts (SACs), but the basic understanding of the mechanism is still lacking. Herein, by constructing h-DACs with different distances of Cu and Ni atoms loaded onto MBenes, the metal atoms loading capacity is significantly increased while maintaining the excellent catalytic activity of SACs. The h-DACs possess more flexible active sites compared to SACs. Controlling the distance between the dual atoms is crucial for the catalytic mechanism and activity. The results indicate that the synergistic effect between the dual metal atoms in h-DACs breaks the scaling relationships between the binding energies of the oxygen intermediates, thereby enhancing the ORR and OER catalytic activity of the corresponding SACs. It is worth noting that when the interatomic distance between Cu and Ni atoms is 3.21 Å, ORR is executed through 4e- *OOH dissociation mechanism and the system exhibits ultra-low ORR and OER overpotentials of 0.16 V and 0.18 V, respectively, far lower than advanced Pt and IrO 2 /RuO 2 of 0.45 V and 0.56/0.42 V, making h-DACs a promising ORR/OER bifunctional electrocatalyst. This work not only provides deep insights into the fundamental understanding of reaction mechanism and catalytic activity for h-DACs but also provides guidance for designing efficient catalysts. [ABSTRACT FROM AUTHOR]

Lignin represents a significant source of aromatic hydrocarbons in the natural world. The production of high-value chemicals from lignin has the great potential to effectively address the issue of fossil energy scarcity. In this study, complex sulfides of nickel‑cobalt bimetallic catalysts were prepared via hydrothermal synthesis and subsequently employed in the catalytic hydrogenolysis of C O bonds present in lignin. A series of complex sulfides Ni 3 S 2 /Co 3 S 4 -CS n -x-T derived from lignin-MOF (n = 0.5, 1, 1.5 and 2; x = 2, 4 and 6; T = 400, 500, 600 and 700 °C), were prepared under different conditions and subsequently employed in the catalytic hydrogenolysis of lignin model compounds. The optimal catalyst Ni 3 S 2 /Co 3 S 4 -CS 1 –4-500 exhibited the highest conversion rate of benzyl phenyl ether (BPE) (about 97.3 %), and the yields of toluene and phenol produced were 49.5 % and 43.6 %, respectively with isopropanol as the reaction solvent and no external H 2. The introduction of element sulfur in catalysts could effectively inhibit the further hydrogenation of generated aromatic chemicals. The catalysts were well characterized, and the results demonstrated that the catalysts exhibited high catalytic activity with an increased loading of active components. This study provided some novel findings for the construction of biomass-based catalysts and the production lignin-derived aromatic chemicals. In this work, a series of complex sulfides of nickel-cobalt bimetallic catalysts were prepared via hydrothermal method and successfully introduced into the catalytic hydrogenolysis of C-O bonds in lignin. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel Fe-based perovskite hybrid catalyst was designed by sol-gel preparation of Ni-substitution of LaFeO 3 containing in-situ growth of metal oxyhydroxide (MeOOH, Me=Mn, Ni, Co). The performances of metal oxyhydroxide-perovskite composites (MeOOH/LaFe 0.5 Ni 0.5 O 3) for peroxymonosulfate (PMS) activation and ofloxacin (OFL) degradation were investigated. CoOOH/LaFe 0.5 Ni 0.5 O 3 exhibited the best OFL degradation efficiency of 91.84 % within 15 min. Compared with LaFe 0.5 Ni 0.5 O 3 , the specific surface area (from 21.391 to 100.216 m2·g−1) and pore volume (from 0.080 to 0.226 cm3·g−1) of CoOOH/LaFe 0.5 Ni 0.5 O 3 increased drastically. Among the structures and properties, substitution of Ni into B-site of LaFeO 3 accelerated the electron transfer and promoted the redox cycle between Fe3+/Fe2+ and Ni2+/Ni0. Besides, doping with CoOOH could provide more active sites for the catalyst and more electrons for the activation of PMS to generate reactive species. The higher redox potential of Co ions resulted in good thermodynamic cycling between Co3+/Co2+, Fe3+/Fe2+ and Ni2+/Ni0. Moreover, oxygen vacancies (V o) on the material surface were involved in the activation of PMS. Quenching experiments and electron paramagnetic resonance (EPR) verified that the catalytic reaction was primarily driven by both ·O 2 - (radical way) and 1O 2 (non-radical way), with electron transfer process (ETP) also had some effect on OFL degradation. In addition, the conversion of radicals to non-radicals was demonstrated. Finally, the degradation pathway of OFL and the ecotoxicity of the intermediates were proposed. The work provided scientific support and theoretical basis for the development of efficient heterogeneous PMS catalysts. [Display omitted] • Hybrid catalyst based on perovskite compositing with metal oxyhydroxide was synthesized. • OFL can be effectively degraded in the novel CH/LFNO/PMS system. • The synergistic effect of free radicals and non-free radicals existed in the system. • Doping CoOOH promoted thermodynamic cycling between Co3+/Co2+, Fe3+/Fe2+ and Ni2+/Ni0. [ABSTRACT FROM AUTHOR]

A novel nitrogen-rich covalent organic framework (CP-COF) is an effective catalyst for the CO 2 cycloaddition. [Display omitted] • Cyanuric chloride, piperazine and 1,4-dioxane precursors were polymerized at 110 ℃ to get N rich porous material CP-COF. • CP-COF showed superior conversion of CO 2 to cyclic carbonate due to its specific properties. • CP-COF exhibited an appropriate amount of product under mild conditions. • CP-COF was capable of recycling and was stable after the 7th run. • This study offers an appropriate way to convert CO 2 into usable products. Carbon dioxide (CO 2) can be chemically converted into high-value products, which is not only helps to ease the environmental problems instigated by global warming and has an optimistic effect on economies around the planet. The production of cyclic carbonates is regarded as a promising approach to convert CO 2 through the cycloaddition of CO 2 with epoxides. However, a major obstacle in this process is the synthesis of environmentally friendly and highly effective heterogeneous catalysts. Here, a novel nitrogen-rich covalent organic framework (CP-COF) was firstly synthesized through a polymerization method of piperazine and cyanuric chloride with 1, 4‐dioxane and used for the aforesaid reaction. A number of analytical methods were employed to verify the chemical composition and the structure of the catalyst. The CP-COF catalyst possessed a significant amount of active nitrogen sites and hydrogen bond donors in it, resulting in a high level of reactivity for the cycloaddition reaction of CO 2 with epichlorohydrin in the absence of any solvent and metals, and the yield of chloropropene carbonate (CPC) reached 99 % at 110 ℃, 6 h and 1 MPa CO 2 pressure. The CP-COF sample exhibited commendable activity towards a range of epoxides. Moreover, it showed high reusability for the reaction without any loss in the catalytic efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ growth strategy enhanced specific surface area and exposure of active sites in CoO x -CN. • The CN substrate affected the characteristics of cobalt crystal planes and the formation of defects. • The roles and generation of reactive species were systematically revealed. • The integrated catalytic membrane system provides a sustainable wastewater treatment solution. Heterogeneous peroxymonosulfate (PMS) activation processes are considered promising Fenton-like oxidation technologies, and the design of heterogeneous catalysts is key to enhancing their practical applicability. In this study, a catalyst consisting of cobalt oxides grown in situ on carbon nitride nanosheets (CoO x -CN) was designed for PMS activation and the degradation of emerging organic contaminants. The CN substrate increased the specific surface area and enhanced the exposure of reactive sites in CoO x -CN, while the NH 3 released during the calcination of CN reduced cobalt species, promoting the formation of sub-valent CoO crystal planes and oxygen vacancies (O V). As a result, the CoO x -CN/PMS system demonstrated efficient tetracycline removal efficiency, reaching 99.4 % within 21 min, with a specific catalytic kinetic constant (K specific) of 0.016 L·min-1m−2. Mechanism studies indicated that the strong electronic interaction between CoO x -CN and PMS induced the generation of reactive species responsible for the degradation of organic contaminants. Based on theoretical calculations, intermediate identification, and toxicity analysis, a degradation pathway and toxicity evolution for tetracycline were proposed. Additionally, the application of CoO x -CN in a membrane system and its performance in treating natural water bodies confirmed its potential for real-scale applications. This work provides a reference for the design of Fenton-like catalysts and their application in actual wastewater treatment scenarios. [ABSTRACT FROM AUTHOR]

[Display omitted] • P-Co@C/PMS system presented >99 % removal efficiency within 10 min. • P accelerated electron transfer and promoted Co(III)/Co(II) redox cycling. • Effects of anions and dissolved organic matters on PMS activation were studied. • DCF degradation pathways were proposed and verified by LC-MS and DFT. • Diclofenac sodium degradation in this system was a toxicity-attenuation process. In order to overcome the low catalytic efficiency of conventional single cobalt-based catalysts, a cobalt-based peroxymonosulfate (PMS) heterogeneous catalyst, named P-Co@C, was synthesized by introducing phosphorus. The degradation rate of diclofenac (DCF) was increased by 5-fold from 0.076 min−1 (Co@C) to 0.426 min−1 (P-Co@C). The enhanced catalytic behavior was ascribed to the increased specific area, promotional hydrophilicity, reduced resistance to electron transfer and improved electron donor of reductive phosphorus. Density functional theory (DFT) calculations suggest that the doped P further facilitates the adsorbability and charge transfer intensity between catalyst and PMS, which benefits the generation of hydroxyl radical, sulfate radical and singlet oxygen. Furthermore, toxicity assessment of the intermediates revealed that the P-Co@C/PMS/DCF system was a diminishing toxicity process, revealing the practicability and eco-friendly of P-Co@C in PMS-based oxidation process. This work provides a new strategy for exploring the cation and anion co-activation of the PMS heterogeneous catalytic systems. [ABSTRACT FROM AUTHOR]

• Spatial confinement effect of Er/Co@NCB was utilized to enhance 4-NP removal rate. • Er-doping regulated the electronic structure of Co sites for PMS activation. • Synergy of confinement effect and electronic modulation facilitate degradation. • Radical and non-radical pathways contributed to the degradation process. The development of efficient strategies to modulate the electron structure of active sites in heterogeneous catalysts is crucial but remains challenging for enhancing peroxomonosulfate (PMS) activation to degrade organic contaminants. In this study, Co-Er-N-doped carbon black materials are successfully synthesized by pyrolyzing the CB@Er/Co-complex precursor. Er-doping does not enhance the defect level or graphitization degree of the carbon matrix, but rather regulates the electronic structure of Co sites, thereby generating abundant metallic Co species for activating PMS and yield increased reactive oxygen species towards 4-nitrophenol (4-NP) degradation. The optimal Er/Co@NCB-0.6 catalyst exhibits a removal efficiency of 97.9 % in 20 min. Furthermore, this catalyst exhibits broad degradation capabilities against various organic contaminants. Due to the spatial confinement effect from carbon layers, the encapsulated Co nanoparticles in the Er/Co@NCB-0.6 catalyst demonstrate excellent stability and reusability for the reaction. Radical quenching and electron paramagnetic resonance results indicate that the Er/Co@NCB-0.6/PMS system involves radical and non-radical pathways, and 1O 2 and SO 4 •− play essential role in degrading 4-NP. The pollutant is degraded into seventeen intermediates via two plausible pathways. This study provides a valuable rare metal-mediated strategy to regulate the electronic structure of Co-based catalytic materials towards activating PMS in removing persistent organic pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] The electro-Fenton (EF) technology holds immense potential for wastewater treatment. However, there persist certain factors that affect its degradation efficiency, such as the restricted pH range, production of iron sludge and sluggish conversion rate between Fe2+ and Fe3+. Herein, 2,3,6,7,10,11-hexahydroxytriphenyl (HHTP) was introduced as the organic ligand to synthesize a series of efficient iron-based MOF catalysts (Fe x Ce 1 -HHTP (x = 1, 2, 3, 4)) with different molar ratios for sulfamethoxazole (SMX) degradation in heterogeneous EF system. HHTP with electron-rich functional groups is beneficial to enhance performance of oxygen evolution reaction. Among these catalysts, Fe 3 Ce 1 -HHTP catalyst achieved 97.3 % degradation efficiency in 30 min and mineralization rate was 89.7 % at 1 h. The introduction of Ce promoted the transition of Fe3+ and Fe2+ in heterogeneous EF reaction. The synergistic effects between Fe3+/Fe2+ and Ce4+/Ce3+ further catalyzed the generation of hydroxyl radicals and it was proved as the main active species. The heterogeneous catalyst showed good performance in wide pH range, good stability, and high degradation efficiency to other pollutants. Three possible SMX degradation routes are suggested on basis of intermediates detected by mass spectrum analysis and theoretical calculations. The toxicity of these intermediates was assessed using Toxicity Estimation Software Tool (T.E.S.T.). This work provides valuable guidance for the design of highly efficient and stable heterogeneous EF catalyst for antibiotic degradation and expand the application potential in wastewater treatment of organic pollutants. [ABSTRACT FROM AUTHOR]

Mechanism analysis of pollutant degradation in CoO x -MMT-300 + PMS system [Display omitted] • MMT can function as a "microchemical reactor" to enhance ROS generation. • A reaction pathway of •O 2 − + Co(IV)/Co(III) → 1O 2 + Co(III)/Co(II) for the predominant 1O 2 generation was revealed. • The confined space could reduce migration distance and enhance utilization of 1O 2. • The prepared membrane demonstrated a long-term stability over 10 h operation. A surface-engineered heterogeneous catalyst with controllable interfaces is the most straight-forward method to boost catalytic activity. However, ensuring the contact of active sites and serving as a highly efficient peroxymonosulfate (PMS) activator for wastewater treatment still face challenges. Herein, CoO x -confined in natural montmorillonite (MMT) was introduced to achieve exceptional reaction rate (0.237 min−1) for sulfamethazine degradation and splendid selectivity of singlet oxygen (1O 2) generation. Particularly, the unique interlayer domain can function as a special "microchemical reactor" to confine contaminants, thus reducing migration distance and enhancing utilization of reactive oxygen species. Meanwhile, the intensified interfacial coupling of reactive Co species with MMT is conducive to elevating Co(II)/Co(III)/Co(IV) conversion. A reaction pathway of •O 2 − + Co(IV)/Co(III) → 1O 2 + Co(III)/Co(II) for the predominant 1O 2 generation was revealed. The prepared membrane demonstrated a long-term stability over 10 h continuous operation at a flux of 360 L m−2h−1 and a retention time of 2450 ms. This study offers a simple design train based on layered structure for environmental-related applications. [ABSTRACT FROM AUTHOR]