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• ZnAlCe catalysts were prepared to catalyze the direct synthesis of GC. • The involvement of CeO2 enhanced the formation of the frustrated Lewis pairs. • Zn4AlCe catalyst presented the highest GC yield of 28.9 %. • Possible formation pathway of GC from CO2 and glycerol was proposed. Zinc-aluminum-cerium composite oxide (ZnAlCe) catalysts were prepared by co-precipitation to catalyze the direct synthesis of glycerol carbonate (GC) from carbon dioxide (CO 2) and glycerol. The characterization results showed that the lattice oxygen served as Lewis basic centers and Ce4+ served as Lewis acidic centers on Zn 4 AlCe catalyst, and frustrated Lewis pairs (FLPs) were formed due to the steric hindrance in the catalyst structure. CO 2 was easily activated by FLPs because the acidic and basic centers of FLPs bound to the oxygen and carbon atoms of CO 2 , respectively. The experimental results indicated that Zn 4 AlCe catalyst presented excellent catalytic performance with good thermal stability and strong regeneration ability. Under the reaction conditions of 0.115 g catalyst, 12 h, 170 °C, 4.5 MPaCO 2 and 5 mL acetonitrile dosage, the GC yield and selectivity were 28.9 % and 51.0 %, respectively. The GC yield is relatively high among similar catalysts reported so far, which lays the foundation for future industrial considerations. [Display omitted] [ABSTRACT FROM AUTHOR]

The Mn-containing mixed-oxide-supported bismuth oxychloride (BiOCl) catalysts were prepared by calcining their corresponding parent hydrotalcite supported BiOCl. The crystal structure of BiOCl was found to be intact during calcination, while significant differences appeared in the chemical state of Mn and the redox capacities of the catalysts before and after calcination. Compared to the hydrotalcite-supported catalysts, the mixed-oxide-supported BiOCl showed much higher catalytic performance in the oxidation removal of formaldehyde due to the synergetic catalysis of more surface oxygen vacancies and higher surface basicity. The complete removal of formaldehyde could be achieved at 70 °C, and the removal efficiency was maintained more than 90% for 21 h. A possible reaction mechanism was also proposed. [ABSTRACT FROM AUTHOR]

Solid frustrated-Lewis-pair catalysts, based on Zn-Al composite oxide modified loaded with Au (Au x /ZnAl-CHT), were prepared by calcination of hydrotalcite precursors and tested for the direct synthesis of glycerol carbonate using CO 2 as the carbon source. An Au 5 /ZnAl-CHT catalyst shows the highest catalytic performance with the glycerol carbonate yield of 19.5 % and the selectivity of 50.5 % at 170 °C and 4.0 MPa CO 2 , while maintaining good thermal stability and excellent regeneration ability. A series of characterization results and density functional theory (DFT) calculations indicated the introduction of Au leads to more frustrated-Lewis-pairs in Zn-Al composite oxide (ZnAl-CHT), which improve the adsorption and activation of CO 2. Meanwhile, FTIR analysis indicates that glycerol is activated by Zn2+ for the formation of zinc glycerolate intermediates. The above dual synergistic activation processes effectively enhance the catalytic performance. And the reaction pathway is proposed for the synthesis of glycerol carbonate from CO 2 and glycerol. [Display omitted] ● Au 5 /ZnAl-CHT exhibited excellent catalytic performance with the yield of 19.5 %. ● Au played a potential "bridge" promoting the formation of FLPs. ● Characterization results and DFT calculations indicated that Au led to more FLPs. ● The reaction mechanism for direct synthesis of glycerol carbonate was proposed. [ABSTRACT FROM AUTHOR]

Abstract: CuNiAl hydrotalcites supported BiOCl were prepared by one-step synthesis for the selective oxidation of glycerol to glyceraldehyde with H2O2 as oxidant. The prepared catalysts were found to be efficient due to the synergetic catalysis of surface oxygen vacancies, active Cu2+ ions in the HT-lattice and abundant surface -OH groups of catalysts. The optimal glycerol conversion could reach 75.4% with 82.4% of the selectivity to glyceraldehyde. Moreover, the catalyst could be reused at least 6 times, and a possible reaction mechanism was also proposed.Graphical Abstract: Inexpensive and environmentally friendly BiOCl/CuNiAl-HTs were synthesized by one-step for the highly selective oxidation of glycerol to glyceraldehyde. The glycerol conversion could reach 75.4% with 82.4% selectivity to GLAD. Such a highly efficient catalytic performance could be attributed to the synergistic effect of oxygen vacancies and the coordination of glycerol on Bi3+ in the supported BiOCl catalyst. [ABSTRACT FROM AUTHOR]

A series of anion intercalated transition metal hydroxides and their calcined mixed metal oxides were prepared for the solvent-free selective oxidation of toluene with O 2 . The results revealed that the anion modified mixed metal oxides showed much better catalytic performance than their parent hydroxides. Moreover, the anions were also found to play important role in the catalytic performance and thermal stabilities of modified catalysts. Unexpectedly, iodide ion exhibited high thermal stability in the mesoporous structures of mixed metal oxides even at high temperatures of 1073 K. Under the optimal reaction conditions, the highest toluene conversion reached 15.5% with 100% of the selectivity to benzaldehyde. [ABSTRACT FROM AUTHOR]

A series of Mg-Al layered-double hydroxides (LDHs) intercalated by sulphonato-Schiff base complexes were prepared for the selective oxidation of glycerol (GLY) with O as oxidant. The results revealed the LDH hosted complexes were effective catalysts, and their catalytic performance were closely related to the structures and composition of catalysts, the base environments of reaction mixtures as well as the reaction conditions. Among them, LDH hosted copper complex displayed the highest catalytic performance, and the GLY conversion could reach 82.5 with 86.1 % of the selectivity to glyceric acid (GLYAC). Moreover, the catalytic performance remained after being recycled seven times. Graphical Abstract: LDH hosted transition metal complex catalysts were promising catalysts for the selective oxidation of GLY to glyceric acid with O. The catalytic performance of catalysts and the product distribution were found to be closely related to the structures and composition of catalysts, the base environments of reaction mixtures as well as the reaction conditions. The best GLY conversion reached 82.5 with 86.1 % of the selectivity to GLYAC.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

By using Mor-DalPhos as the P, N-bidentate ligand and mesylate as the counter ion, the resulting gold(I) complex catalyzes efficient oxidative transformations of various terminal alkynes into synthetically versatile methanesulfonyloxymethyl ketones. The mild reaction conditions and high efficiency permit the one-pot synthesis of a range of valuable 2,4-disubstituted thiazoles by subjecting the resulting reaction mixture to a further condensation with thioamides under mild conditions. [ABSTRACT FROM AUTHOR]

Three amphiphilic sulphonato-salen-chromium(III) complexes immobilized on MCM-41 were prepared for the solvent-free selective oxidation of benzyl alcohol with 30 % hydrogen peroxide. The immobilized complexes were effective catalysts and exhibited much higher catalytic performance than their corresponding homogeneous analogues and immobilized lipophilic complexes. Under the optimum reaction conditions, benzyl alcohol conversion could reach 60.3 % with 100 % of the selectivity to benzaldehyde. In addition, the catalysts could be recycled at least five times. Graphical Abstract: The immobilized amphiphilic sulphonato-salen-chromium(III) complexes were effective in the selective oxidation of benzyl alcohol due to the increased accessibility of oxidant to catalyst and reactant. The best benzyl alcohol conversion reached 60.3% with 100% of the selectivity to benzaldehyde.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Highlights: [•] Reaction was performed over low-cost transition metal catalysts. [•] Heterogeneous catalysis and recyclability of the catalyst. [•] Conversion of glycerol reached 68.1% with 76% of the selectivity to glyceric acid. [ABSTRACT FROM AUTHOR]

A series of transition metal complexes of 3-[ N, N′-bis-3-(salicylidenamino)ethyltriamine] (salten) immobilized on MCM-41 were prepared for the solvent and additive-free selective oxidation of cyclohexanol with 30 % hydrogen peroxide (HO). The immobilized complexes were effective catalysts and exhibited much higher catalytic performance than their homogeneous analogues. Moreover, the metal centers were found to play important roles in the catalytic performance of immobilized complexes. When the immobilized chromium complex was used as catalyst, the optimal cyclohexanol conversion could reach 90.5 % with 100 % of the selectivity to cyclohexanone. In addition, the catalytic performance remained after being recycled five times. Graphical Abstract: Owing to the different 3d electronic numbers of metal centers, eight kinds of immobilized Schiff base complexes exhibited significantly different catalytic performance in the selective oxidation of cyclohexanol with 30 % HO. The optimal cyclohexanol conversion could reach 90.5 % with 100 % of the selectivity to cyclohexanone over immobilized chromium complex.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A Mgd-double hydroxides (LDH) intercalated by sulphonato-salen-chromium(III) complex was used to the selective oxidation of glycerol (GLY) using 3% H2O2 as oxidant. The results revealed that the LDH hosted chromium complex was effective heterogeneous catalyst. And the main product was the C3 oxygenated products of secondary alcohol‐dihydroxyacetone (DHA). Under the optimal reaction conditions, the highest conversion of GLY reached 73.1% with 43.5% of the selectivity to DHA. Moreover, the catalytic performance remained after being recycled 6 times. In addition, the reaction probably involved an enzyme mimetic mechanism. [Copyright &y& Elsevier]

Abstract: The fluorine-modified Mg–Al mixed oxides were synthesized by thermal decomposition of the fluorine-containing Mg–Al hydrotalcites, and their physicochemical properties were characterized by ICP, TGA, XRD, FTIR, CO2-TPD and N2 adsorption/desorption techniques. It was found that weak basic sites were gradually transformed into moderate and strong basic sites during thermal decomposition, and thus weak basic sites (OH− groups), moderate basic sites (Mg–O, Mg–F and Al–O pairs) and strong basic sites (coordinatively unsaturated F− and O2− ions) were all produced in the as-prepared samples. Furthermore, the basicity of moderate basic sites could be controlled by the change of fluorine content, which caused the change in the amounts of Mg–F pairs. In the synthesis of propylene glycol methyl ether from methanol and propylene oxide, the base-catalytic performance of the obtained samples was shown to be closely associated with their moderate basic sites. [Copyright &y& Elsevier]

Abstract: The Mg–Al layered-double hydroxides (LDHs) intercalated by three kinds of sulphonato-salen-chromium(III) complexes were prepared and characterized by FTIR, UV–vis, XRD and elemental analysis. It was found that the homogeneous complexes were successfully intercalated into the LDH interlayer via the method of anion exchange followed by coordination with chromium(III) chloride. And the resulting LDH hosted chromium complexes were shown to be effective heterogeneous catalysts for the solvent-free oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using 30% H2O2 as oxidant. Furthermore, owing to the different local environment of the central metal ion chromium(III), the catalyst with the backbone of o-C6H4 displayed the highest catalytic performance followed by the NH(CH2CH2)2 with the (CH2)2 showing the lowest BzH yield. In addition, a tentative mechanism was also discussed. [Copyright &y& Elsevier]

Abstract: A series of Cr(salen) complexes immobilized on MCM-41 via four typical linkers was prepared for the selective oxidation of benzyl alcohol (BzCH2OH) to benzaldehyde (BzCOH). The results revealed that the complex-immobilized materials were effective catalysts and all exhibited much higher catalytic performance than their homogeneous analogue. Simultaneously, the catalytic performance of complex-immobilized materials was found to be closely related to the degree of flexibility of the linkers and the coordination abilities of terminal functional groups in linkers. The complex-immobilized via flexible aminopropyl linker displayed the highest catalytic performance, and the optimal BzCH2OH conversion could reach 52.5% with 100% of the selectivity to BzCOH. [Copyright &y& Elsevier]

Abstract: A series of fluorine-modified Mg–Al mixed oxides were synthesized by thermal decomposition of the fluorine-containing Mg–Al hydrotalcites and then were characterized by ICP, TGA, XRD, FTIR, CO2-TPD and N2 adsorption/desorption technique. The results revealed that the mesoporous structure was formed during calcination and that fluorine was successfully introduced into the Mg–Al mixed oxides via the phase of MgF2. Simultaneously, such fluorine-modified Mg–Al mixed oxides were effective catalysts for the O-methylation of phenol with dimethyl carbonate (DMC), and their catalytic performance was found to be closely correlated with their basicity. With the optimal catalyst composition, the highest yield of anisole reached 99.3%, with a DMC/phenol molar ratio of 2 at 473K. [Copyright &y& Elsevier]

CeO2-ZrO2-La2O3 supported Pt-Pd bimetallic three-way catalysts (0.6Pt-0.4Pd/CZL) were synthesized through the conventional impregnation method and then subjected to severe thermal aging. Reactivating treatments under different temperatures were then applied to the aged catalysts above. Three-way catalytic performance evaluations and dynamic operation window tests along with detailed physio-chemical characterizations were carried out to explore possible structure–activity evolutions during the reactivating process. Results show that the reactivating process conducted at proper temperatures (500~550 °C) could effectively restore the TWC catalytic performance and widen the operation window width. The suitable reactivating temperature ranges are mainly determined by the decomposing temperature of PMOx species, the thermal stability of PM-O-Ce species, and the encapsulation temperature of precious metals by CZL support. Reactivating under appropriate temperature helps to restore the interaction between Pt and CZL support to a certain extent and to re-expose part of the encapsulated precious metals. Therefore, the dynamic oxygen storage/release capacity, redox ability, as well as thermal stability of PtOx species, can be improved, thus benefiting the TWC catalytic performances. However, the excessively high reactivating temperature would cause further embedment of Pd by CZL support, thus leading to a further decrease in both dynamic oxygen storage/release capacity and the TWC catalytic performance after reactivating treatment. [ABSTRACT FROM AUTHOR]

• Multi-layer core-shell structure was fabricated without any template. • Ag was modified in situ by photochemical deposition to improve stability. • S-scheme and SPR effect endued heterojunction with an excellent redox capacity. • Reactive species trapping was conducted to ensure the dominant species. • Introducing oxygen during catalytic process can augment degradation efficiency. Constructing an efficient photocatalyst to accelerate charge separation with strong redox capacity is in pursuit all the way. Herein, a novel heterojunction was achieved for efficient organic degradation, which took advantages of S-scheme mechanism, metal surface plasma resonance (SPR) and unique morphology. The multi-layer core-shell structure can be regulated by aging time with template-free, and Ag nanoparticles were modified on the heterojunction by photochemical deposition in situ to facilitate electron transport and improve stability. S-scheme and SPR endues the heterojunction with broad light absorption, increased light utilization, efficient carrier separation, and strong redox capacity. An examination of reactive dynamics revealed that superoxide radicals and hydroxyl radicals are crucial for oxidative degradation. Introducing oxygen during the reaction process has been found to enhance the efficiency by 7 %. This article furnishes novel insights into a coordination of energy band engineering, structure regulation, as well as reaction process adjustment for facilitating photo-degradation reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous ZnO-CdS/Pt spherical-shell was fabricated without any template. • Heterostructure presented an efficient H 2 -production rate of 32.15 mM·h−1·g−1. • The exceptional structure improved light trapping and adsorption capacity. • S-scheme endued heterojunction with an excellent redox capacity. • The photo-generated electrons would be transferred rapidly from CdS to Pt. S-scheme heterojunctions present excellent photocatalytic performance for water splitting. Herein, an ideal distinctive heterostructure of porous ZnO-CdS/Pt spherical-shell was achieved by template-free method. It possesses the H 2 -generated efficiency of 32.15 mM·h−1·g−1, significantly surpassing the single or binary compounds. The remarkable photocatalytic activity stems from the unique morphology, S-scheme mechanism and the coordination of noble metal. Exceptional porous spherical-shell structure can localize the light, promote light scattering, increase adsorption capacity and bring abundant active sites. The reduction in transfer distance for carriers, inhibition of electron-hole recombination, as well as diminution of mobility resistance endues the heterojunction with efficient carrier separation and strong redox capacity. The probable mechanism was also estimated by the characterizations of XPS, UV, PL, PEC, EIS, M-S and ESR. This article provides a new method for spherical-shell structure fabricated without template, and proposes a significant promise for the construction and application of highly efficient photocatalysts for H 2 -production. [ABSTRACT FROM AUTHOR]

Plasmonic heterojunctions present excellent photocatalytic performance for water splitting. Herein, a novel S-scheme heterojunction of CdS-ZnO nanorods assisted with low-content Au (<1 wt%) plasmon was achieved successfully, which possessed the H 2 -generated efficiency of 14.36 mM h−1 g−1. Remarkable catalytic activity stems from the S-scheme mechanism, metal plasma resonance and the unique flower-shaped morphology. S-scheme endues the heterojunction with efficient carrier separation and strong redox capacity, and surface plasmon resonance (SPR) generated from low-content Au broadens light absorption range and injects hot electrons into the heterojunction. In-situ XPS measurements verified an S-scheme carrier migration mechanism as well as hot electrons transfer. Other optical and photoelectric characterizations, as well as simulation calculation by finite difference time domain (FDTD) were also utilized to conjecture the probable mechanism. Low content noble metal and unique morphology accelerate the photocatalytic H 2 -production, and it likely proposes the promising strategy for practical application of photocatalysis for solar energy conversion. [Display omitted] • Three-dimensional flower-like structure is composed of nanorods. • Heterostructure presented an efficient H 2 -production rate of 14.36 mM h−1 g−1. • SPR of low-content Au accelerated photocatalytic hydrogen production. • In-situ XPS verified S-scheme carrier migration and SPR hot electrons transfer. • S-scheme endued heterojunction with an excellent redox capacity. [ABSTRACT FROM AUTHOR]

In this work, Cu-Mn oxide catalysts supported on ZSM-5 zeolite (Cu7Mn3Ox/ZSM‑5) were modified by low-cost method of acid leaching and employed for the catalytic oxidation of toluene. For investigating the effect of acid modification on catalysts deeply, the prepared materials were characterized by N2 adsorption–desorption, XRD, SEM, H2-TPR, XPS, NH3-TPD, Py-IR and TG. In the decomposition of toluene, the citric acid modified Cu7Mn3Ox/ZSM‑5 exhibited excellent performance of toluene conversion and adsorption compared to Cu7Mn3Ox/ZSM‑5. The preferable performance was associated with the improved pore structure and surface area, along with the more Mn4+ and Cu2+ species formed after citric acid modification. Significantly, citric acid modified Cu7Mn3Ox/ZSM‑5 exhibited satisfied hydrothermal stability and good regeneration ability as well, which would offer an economical strategy to prepare effective catalysts for VOCs treatment. [ABSTRACT FROM AUTHOR]

A series of transition metal oxides or mixed oxides supported nano-Au catalysts were prepared for the selective oxidation of glycerol to glyceric acid using 3% H2O2. It was found that the composition and structure of supports significantly influenced the catalytic performance of catalysts. The mesoporous trimetal mixed oxide (CuNiAlO) supported nano-Au catalysts were more active in comparison with the others. In the present catalytic system, the highest glycerol conversion was 90.5%, while the selectivity of glyceric acid could reach 72%. Moreover, the catalytic performance remained after 11 times of reaction. [ABSTRACT FROM AUTHOR]

5Cu-USY and Ce-doped 5Cu8Ce-USY zeolite catalysts were prepared by the conventional impregnation method. The obtained catalysts were subjected to the hydrothermal ageing process. The catalytic performance of the selective catalytic reduction of NOx with NH3 (NH3-SCR) was evaluated on both fresh and aged catalysts. Physical/chemical characterizations such as X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS) were performed, along with detailed in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) experiments including CO adsorption, NH3 adsorption, and NO + O2 reactions. Results showed that, for the 5Cu-USY catalyst, hydrothermal ageing treatment could somehow improve the low-temperature SCR activity, but it also led to significant formation of unfavorable byproducts NO2 and N2O. Such an activity change can be attributed to hydrothermal ageing inducing the migration of isolated Cu+ species in the sodalite cavities towards the super cages of the USY zeolites. The increased content of Cu+ species in the super cages was beneficial for the low-temperature activity improvement, but, at the same time, it also facilitated ammonia oxidation at high temperatures. Ce doping after hydrothermal ageing has a "double-edged sword" effect on the catalytic performance. First of all, Ce doping can inhibit Cu species migration by self-occupying the internal cage sites; thus, the catalytic performance of 5Cu8Ce-USY-700H remains stable after ageing. Secondly, Ce doping introduces a CuOx–CeO2 strong interaction, which facilitates lattice oxygen mobility by forming more oxygen vacancies so as to increase the concentration of surface active oxygen. These changes, on the one hand, could help to promote further oxidative decomposition of nitrate/nitrite intermediates and improve the catalytic performance. But, on the other hand, it also causes the byproduct generation to become more severe. [ABSTRACT FROM AUTHOR]

1,4-Dioxenes and 4,7-dihydrooxepines present interesting potential as motifs for the incorporation of biologically relevant molecules, agrochemicals and materials. In this study, two efficient intermolecular (3 + 2 + 1) and (5 + 2) cycloadditions for the synthesis of 1,4-dioxenes and 4,7-dihydrooxepines are achieved with gold catalysis. [ABSTRACT FROM AUTHOR]

A series of Cu‐containing trimetal mixed oxides supported nano‐Au catalysts were prepared and characterized by XRD, N2 sorption, elemental analysis and H2‐TPR. Then, their catalytic performance was firstly investigated in the selective oxidation of glycerol with 3% H2O2 or O2 as oxidants. It was found that both the elemental components of mixed oxides and the types of oxidant influenced remarkably the catalytic performance of the supported catalysts and the product distributions. Under the optimal reaction conditions, the highest yield of main product glyceric acid reached 66.5% over CuMnAl mixed oxide supported nano‐Au catalyst in the presence of O2. Moreover, the catalyst could be reused several times. In addition, the catalyst was further used in the selective oxidation of benzyl alcohol and cyclohexanol, and the best yield of benzaldehyde and cyclohexanone were 72.5% and 96.0%, respectively. [ABSTRACT FROM AUTHOR]

The hollow CeO2 (H‐CeO2) nanoparticles with mesoporous defects structure were prepared by a solid template method under ambient pressure and applied to catalyze the conversion of CO2 into dimethyl carbonate (DMC). The textural properties of H‐CeO2 were investigated by various characterization techniques. The results showed that H‐CeO2 have higher surface area, more mesoporous defects and higher surface oxygen vacancies concentration than those of conventional CeO2 with block morphology (C‐CeO2). Therefore, H‐CeO2 exhibited better catalytic performance for the conversion of CO2 into DMC. Additionally, the Ce(NO3)3 ⋅ 6H2O amount in preparation procedure was important for the formation of hollow structure and mesoporous defects. The DMC yield could reach 4.96 % on H‐CeO2‐1.2 (Ce(NO3)3 ⋅ 6H2O amount: 1.2 g) catalyst when the reaction was performed at 140 °C and 4.5 MPa for 4 h. This work proposed a facile strategy for designing CeO2 catalysts for the CO2 conversion by creating mesoporous defective structure. [ABSTRACT FROM AUTHOR]

A series of supported MnOx/MgAl-layered double hydroxide (LDH) catalysts were prepared by hydrothermal co-precipitation to investigate their catalytic performances for low-temperature formaldehyde oxidation reactions. Activity tests show that the 10Mn/Mg3Al1-LDH catalyst exhibits higher efficiency for low-temperature formaldehyde oxidation with a high CO2 yield. It also shows remarkable long-term operational stability as well as good adaptability to different velocities and humidities. Various characterizations were carried out to establish the possible structure–activity correlations. The results show that there were a large number of hydroxyl groups in the 10Mn/MgAl-LDH catalysts, and the hydroxyl groups were positively correlated with Mg2+ content. The outstanding catalytic performance of 10Mn/Mg3Al1-LDH can be attributed to abundant surface hydroxyl groups, surface adsorbed oxygen and higher Mn4+/Mn3+ ratios. Through in situ Fourier-transform infrared spectroscopy (in situ FTIR), it was revealed that formaldehyde was gradually converted into CO2 and water with dioxymethylene (DOM), formate and carbonate as the major intermediates under the action of both active oxygen and active hydroxyl groups. The active oxygen and active hydroxyl groups consumed in the process are continuously replenished by the effective reaction between the oxygen molecules in the air and the active site of the catalyst. The low-temperature asynchronous conversion of formaldehyde results in the accumulation of some intermediates on the catalyst surface covering the active center, which induces catalyst deactivation. [ABSTRACT FROM AUTHOR]

An efficient synthesis of ketones (III) and thiazoles (VI) is achieved by trapping in-situ generated α-oxo gold carbenes with MesOH or thioamides (V), respectively. [ABSTRACT FROM AUTHOR]

A series of mesoporous nano-MgO-ZrO 2 with various Mg:Zr atomic ratios were prepared via simple co-precipitation process without addition of a template. It was demonstrated by XRD, N 2 adsorption-desorption and TEM that these samples still kept well mesoporous structure even after calcination at 600 °C. During the preparation process, divalent Mg 2+ ions could be incorporated into tetragonal ZrO 2 lattice to form a solid solution. More important, the surface basic density of these catalysts closely depended on their Mg content. Then, the resulting MgO-ZrO 2 catalysts were used as basic catalysts for the dipropyl carbonate (DPC) synthesis via transesterification of n -propanol and dimethyl carbonate. The relationship between the basic property of solid base and their catalytic performance was clarified in detail. Among all the materials, the catalyst with Mg:Zr atomic ratio = 0.5 showed the best catalytic performance. Under the suitable reaction conditions, the yield of DPC could reach 98.5% with 100% selectivity. In addition, based on the reusability test and catalyst characterization, this catalyst exhibited extraordinary structure stability and it could be reused at least four times without obvious loss of reactivity. [ABSTRACT FROM AUTHOR]

Series of Cu-USY zeolite catalyst with different Cu loading content were synthesized through simple impregnation method. The obtained catalysts were subjected to selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) performance evaluation, structural/chemical characterizations such as X-ray diffraction (XRD), N 2 adsorption/desorption, H 2 temperature-programmed reduction (H 2 -TPR), NH 3 temperature-programmed desorption (NH 3 -TPD) as well as detailed in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments including CO adsorption, NH 3 adsorption and NO+O 2 in situ reactions. Results show that Cu-USY with proper Cu loading (in this work 5Cu-USY with 5 wt.% Cu) could be promising candidates with highly efficient NH 3 -SCR catalytic performance, relatively low byproduct formation and excellent hydrothermal stability, although its SO 2 poisoning tolerability needs alleviation. Further characterizations reveal that such catalytic advantages can be attributed to both active cu species and surface acid centers evolution modulated by Cu loading. On one hand, Cu species in the super cages of zeolites increases with higher Cu content and being more conducive for NH 3 -SCR reactivity. On the other hand, higher Cu loading leads to depletion of Brønsted acid centers and simultaneous formation of abundant Lewis acid centers, which facilitates NH 4 NO 3 reduction via NH 3 adsorbed on Lewis acid centers, thus improving SCR reactivity. However, Cu over-introduction leads to formation of surface highly dispersed CuO x , causing unfavorable NH 3 oxidation and inferior N 2 selectivity. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanoflower-like MoS2 deposited on the surface of rectangular CaTiO3(CTO) was designed and synthesized via a simple template-free strategy. Through SEM, TEM, and other characterization methods, the MoS2 nanoflowers were confirmed to be well deposited on the surface of CTO. LED was used as the visible light source, and rhodamine B (RhB) in an aqueous solution was used as the model pollutant to assess the photodegradation activity of the samples. The results showed that the MoS2/CaTiO3(MCTO) composite significantly improved the photocatalytic degradation of rhodamine B (RhB) in water, compared with a single CTO, and with the MCTO-2 composite photocatalysts, 97% degradation of RhB was achieved in 180 min, and its photocatalytic activity was about 5.17 times higher than that of the bare CTO. The main reasons for enhancing photocatalytic performance are the strong interaction between the nanoflower-like MoS2 and rectangular CTO, which can lead to the effective separation of electron transfer and photoexcited electron–hole pairs in MCTO composites. This work provides a new notion for researching an effective method of recycling catalytic materials. [ABSTRACT FROM AUTHOR]

Series of Ti/Cu-SSZ-13 zeolite catalysts with variable Ti content were prepared via convenient in-situ one-pot synthesizing strategy. Systematic evaluations of the NH3-SCR catalytic performance over the obtained catalysts were conducted. Results show that Ti/Cu-SSZ-13 with appropriate Ti content (in the current work Ti0.81/Cu2.15-SSZ-13) could serve as capable candidate for NH3-SCR application, as it exhibits highly efficient catalytic activity with expanded operation temperature window width from 140 to 540 °C, nearly 100% N2 selectivity, as well as superior tolerability against water vapor and SO2. Further structural/physicochemical characterizations demonstrate that the obtained Ti/Cu-SSZ-13 catalysts possess well-crystallized characteristic chabazite (CHA) structure. Isolated Cu2+ and monomeric Ti4+ are recognized as the primary active species, as the former mainly contributes to SCR reaction at low temperatures, while the latter are conducive for improving the high temperature SCR activity. Ti over doping would result in partial destruction of the zeolite structure, occupation of Cu2+ cation sites and formation of surface aggregated TiOx, thus leading to unsatisfactory NH3-SCR performances. Moreover, formation of agglomerated CuOx species during hydrothermal ageing and blockage of surface active sites by sulfate species formed during SO2 pretreatment are considered responsible for activity deterioration in the tolerability tests. [ABSTRACT FROM AUTHOR]

CeO 2 –ZrO 2 mixed oxides with controlled morphologies (i.e., nanorod, nano-polyhedral and disordered shape) were synthesized through either hydrothermal or coprecipitation method, and the corresponding supported Pd/CeO 2 –ZrO 2 catalysts were also prepared by conventional impregnation. The obtained catalysts were subjected to systematic structural/physio-chemical characterizations as well as three-way catalytic performance evaluations. The results showed that CeO 2 –ZrO 2 mixed oxides presented different exposed crystal planes: namely disordered CZ-di mainly exposed (111) crystal planes, nanorod CZ-ro mainly exposed (111) crystal planes and few (100) crystal planes, while nano-polyhedral CZ-po exposed both (111) and (100) crystal planes. Clear structure-activity relationship could be demonstrated between the TWC (Three-way catalysts) performance of Pd/CeO 2 –ZrO 2 and such different microstructures, as (100) and (111) crystal planes exposed by CZ-ro and CZ-po were beneficial for the surface oxygen vacancies formation, thus increasing the Pd-support interaction and effectively decreasing the light-off temperature of HC and NO elimination. On the other hand, the disordered CZ-di retained more lattice oxygen content, leading to better catalytic activity of CO elimination for the corresponding Pd/CZ-di catalyst. Pd/CeO 2 –ZrO 2 with different morphologies presents different exposed crystal planes, and clear structure-activity relationship can be demonstrated between TWC performance and morphology control induced microstructures. [Display omitted] • Morphology controlled CeO 2 –ZrO 2 nano-oxides were synthesized. •Different exposed crystal planes modulated via morphology control. •Structure-activity relationship induced by morphology control demonstrated. •Exposed (100) plane of CZ-po promotes surface V O formation for better HC and NO activity. •Lattice oxygen content retained on disordered CZ-di and favors CO activity. [ABSTRACT FROM AUTHOR]

In this study, UiO-66 @CeO 2 composites was prepared by loading CeO 2 nanoparticles on the surface of UiO-66 using precipitation method, and the effect of CeO 2 loading on the catalytic direct reaction of CO 2 and methanol into dimethyl carbonate (DMC) was investigated. XRD, N 2 adsorption-desorption, FT-IR, XPS, SEM and TEM were used to investigate the physical and chemical properties of UiO-66 @CeO 2. The results showed that the framework structure of UiO-66 benefit the high dispersion of CeO 2 , while the loading of CeO 2 provided more oxygen vacancies, which promoted the capture and absorb of CO 2 , thus promoted the reaction synergistically. Among which, UiO-66 @CeO 2 -60 showed best activity, with the highest DMC formation rate of 2.84 mmol·g−1·h−1 (yield: 2.27%) within 4 h of reaction time under the optimum conditions. In addition, the catalyst also showed favorable reusability, maintaining ∼90% of catalytic efficiency with 4 reuse cycles compared the fresh ones. [Display omitted] • Core-shelled UiO-66 @CeO 2 composite catalysts are prepared. • The catalyst shows good catalytic efficiency for the directly synthesis of DMC. • Integrate and synergistic effects of UiO-66 @CeO 2 are concluded. [ABSTRACT FROM AUTHOR]

• Mn 8 Ni 2 Ce a O x (a = 0–1.5) catalysts synthesized via co-precipitation strategy. • Mn 8 Ni 2 CeO x showed excellent catalytic activity and water resistance for toluene. • Ce doping accelerated the oxidation of benzyl alcohol/benzoate intermediates. • Ce doping could inhibit H 2 O adsorption on the catalyst surface. A series of metal oxides Mn 8 Ni 2 Ce a O x (a = 0–1.5) catalysts were prepared by hydrothermal co-precipitation to investigate the effect of Ce doping on manganese-based oxides for toluene catalytic combustion reaction. Activity evaluations show that Mn 8 Ni 2 CeO x (a = 1) catalyst exhibits highly efficient toluene oxidation activity and high yield to CO 2 production. Durability tests reveal that it has remarkably superior water resistance ability and promising potential for practical application. Various characterizations were conducted to explore possible structure-activity correlations. Results show that Ce introduction could construct the strong Ce-Mn interactions, generate more oxygen vacancies, facilitate lattice oxygen mobility, and increase the content of surface active oxygen. These changes efficiently utilize active oxygen species and accelerate the deep oxidation of benzyl alcohol/benzoate intermediates, therefore render activity advantages. Otherwise, Ce doping can effectively maintain the catalyst's structural stability while simultaneously inhibiting H 2 O adsorption on the catalyst surface under humid atmosphere, thus being conducive to the outstanding durability and water resistance ability. Mn8Ni2CeaOx (a = 0–1.5) synthesized via hydrothermal co-precipitation strategy exhibits highly efficient catalytic activity as well as superior water resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

• ZnO/CdS clustered nanotube on the FTO is synthesized by hydrothermal methods. • Hydrogen evolution rate of ZnO/CdS is 7669 μmol g-1h−1 with the AQE of 55.25 %. • S-scheme mechanism enhances the high separation efficiency of carriers. • The recovery rate of ZnO/CdS on FTO substrates is over 99% after 2 circles. Herein, a cluster-like ZnO/CdS nanotube heterojunction photocatalyst was prepared on an FTO conductive glass substrate by a two-step hydrothermal method. The photocatalytic performance and electron transfer mechanism of ZnO and ZnO/CdS composite structures were analyzed through comparing the hydrogen production efficiency of ZnO and ZnO/CdS. The photocatalytic hydrogen production activity of ZnO/CdS (molar ratio 1:1) achieved 7669 μmol/g/h with the AQE of 55.25 %. Unique clustered tubular structure, wider light absorption range and higher carrier transfer rate endowed the composite with marvellous photocatalytic hydrogen production activity. In addition, the measurement of hydroxyl radicals and ESR verified that the electron transfer mechanism followed the S-scheme, which improved the separation efficiency of electron-hole pairs. The residual ratio of catalysts on the FTO substrate remained above 99 % after two cycles, which was remarkably higher than that of the powder catalyst (63 %). This work provides terrific potential for high-efficient, low-cost and recyclable photocatalysts of hydrogen production in the future. [ABSTRACT FROM AUTHOR]

The catalytic advantages of CeO 2 -MnO x catalysts for CB deep oxidation can be attributed to both the unique morphology effect and the Ce-Mn strong interaction in the nano rod shaped. [Display omitted] • CeO 2 -MnO x nano rods with different Ce/Mn molar ratios were synthesized. • Microstructure of CeO 2 -MnO x was analyzed by XRD Rietveld refinement. • CeO 2 -MnO x nano rod exposing defective {1 0 0} facet generates more oxygen vacancies. • Tunnel-like structured todorokite/vernadite phase favors lattice oxygen migration. • Increasing Mn content enriched surface Mn4+ and promoted Ce-Mn redox cycles. Series of nano rod shaped CeO 2 -MnO x catalysts with different Ce/Mn molar ratios were synthesized through facile hydro-thermal method and subjected to chlorobenzene (CB) complete catalytic oxidation tests. Detailed structural/chemical characterizations such as TEM/HRTEM, Rietveld XRD, N 2 adsorption/desorption, UV-Raman and H 2 -TPR were conducted. Results show that the designed nano rod shaped CeO 2 -MnO x binary oxides can be promising with highly efficient catalytic performance towards the complete oxidation of CB. The Ce/Mn-1/8 catalyst (Ce/Mn molar ratio 1:8) is verified as the most outstanding candidate among all the CeO 2 -MnO x catalysts obtained, which not only presents best catalytic activity but also gives less production of hazardous polychlorinated byproducts, along with excellent durability. Further characterizations reveal that such catalytic advantages can be attributed to both the unique morphology effect and the Ce-Mn strong interaction in the nano rod shaped CeO 2 -MnO x catalysts. The designed nano rod shaped CeO 2 -MnO x catalyst mainly exposes the more defective {1 0 0} facet, generating lattice micro-strain and favorable for forming more oxygen vacancies. While the formation of todorokite/vernadite phase with special tunnel-like structure which promoting the migration of lattice oxygen to catalyst surface. Moreover, the strong interaction between CeO 2 and MnO x can promote the (Ce4+/Ce3+ ↔ Mn4+/Mn3+) redox cycles and is beneficial for CB deep oxidation. Increasing Mn content leads to higher content of todorokite/vernadite phases, surface Mn4+ enrichment and shorter nano rods with more exposes lattice defects, thus rendering enhanced Ce-Mn strong interaction and morphology effect in Ce/Mn-1/8 catalyst. [ABSTRACT FROM AUTHOR]

A series of Au–silica (nanosphere) catalysts were prepared by in situ synthesis; highly dispersed gold nanoparticles (GNPs, 6.4 nm) were obtained, and catalytic tests showed good catalytic activity and epoxidation selectivity. To investigate the origin of the GNPs, the solids were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and other instruments. Some reaction parameters, such as solvent, oxidant concentration, catalyst concentration and reaction time, have been investigated and reaction conditions are optimized. [ABSTRACT FROM AUTHOR]

• Column with side reactor configuration for ethylene glycol was proposed. • Detailed combinations of reaction and separation were systematically discussed. • Specified reactor-separation configuration gives better performance. • Operation conditions play important effect on process intensification and economics. The side reactor concept (SRC), comprising a non-reactive column coupled with side reactors, is proposed for the synthesis of ethylene glycol (EG) by ethylene oxide (EO) hydration. Parallel isothermal continuous stirred tank reactors are employed and the combinations of the reactors and the column are cautiously examined. A preliminary analysis of the operating conditions for the reaction and separation and the detailed SRC configurations (such as the side stream rate, side stream location) are performed to generate the suggested values or ranges for their further optimization. The decisive variables are subsequently optimized by a sequential design procedure. The significant effects of the key decision variables on the trade-off between the reaction cost and the separation cost are well investigated. The reactor–separation unit, configured with a total liquid withdrawn and recycled back to the column stage below, demonstrates better system performance. Furthermore, the reaction at elevated temperature (150 °C) conductive for reaction and the separation occurring at the distillation temperature range of 106∼204 °C (124 kPa) gives out improved economic performance. Flexibility in the operating conditions in SRC makes it a competitive alternative to the RD process for EG production. [ABSTRACT FROM AUTHOR]