An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer...An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer vesicles formed from a hexavanadate cluster functionalized with two alkyl chains are highly efficient catalysts for the oxidation of 3,3＇,5,5＇-tetramethylbenzidine （TMB） with H2O2 at room temperature, a widely used model reaction mimicking the activity of peroxidase in biological catalytic oxidation processes. Driven by hydrophobic interactions, the double-tailed hexavanadate-headed amphiphiles can self-assemble into bilayer vesicles and create hydrophobic domains that segregate the TMB chromogenic substrate. The reaction of TMB with H2O2 takes place at the interface of the hydrophilic and hydrophobic domains, where the reagents also make contact with the catalytic hexavanadate clusters, and it is approximately two times more efficient compared with the reactions carried out with the corresponding unassembled systems. Moreover, the assembled vesicular system possesses affinity for TMB comparable to that of reported noble metal mimic nanomaterials, as well as a higher maximum reaction rate.展开更多
Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil en...Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil energies,while such a process is limited by chemical inertia and thermal stability of the CO_(2) molecule and complex hydrogenation routes.In this review,we first summarized the recent progresses of metal-oxide nanocatalysts considered as a category of the most promising catalysts in CO_(2) hydrogenation to value-added C1 chemicals including CH_(4)/CO,formic acid/formate,and methanol.These studies involve with different structural factors affecting the metal-oxide interfacial catalysis including the structures of both the metals(type,particle size,morphology/crystal plane,and bimetal alloy)and the supports(type,particle size,crystal phase,morphology/crystal plane,and composite)and their(strong)metal-support interactions so as to identify the key factor determining the reaction activity,product selectivity,and catalytic stability in CO_(2) hydrogenation.Finally,we further discuss challenging coupling with future research opportunities for tunable interfacial catalysis of metal-oxide nanocatalysts in CO_(2) conversion.展开更多
Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural(HMF)oxidation,promoting the catalytic performance at low loading amounts still remains a significant challenge.Herein,a series of met...Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural(HMF)oxidation,promoting the catalytic performance at low loading amounts still remains a significant challenge.Herein,a series of metal oxide modified MO_(x)-Au/TiO_(2)(M=Fe,Co,Ni)catalysts with low Au loading amount of 0.5 wt%were synthesized.Addition of transition metal oxides promotes electron transfer and generation of the Au^(δ-)-O_(v)-Ti^(3+)interface.A combination study reveals that the dual-active site(Au^(δ-)-O_(v)-Ti^(3+))governs the catalytic performance of the ratedetermining step,namely hydroxyl group oxidation.Au^(δ-) site facilitates chemisorption and activation of O_(2) molecules.At the same time,O_(v)-Ti^(3+) site acts as the role of“killing two birds with one stone”:enhancing adsorption of both reactants,accelerating the activation and dissociation of H_(2)O,and facilitating activation of the adsorbed O_(2).Besides,superoxide radicals instead of base is the active oxygen species during the rate-determining step.On this basis,a FDCA yield of 71.2% was achieved under base-free conditions,complying with the“green chemistry”principle.This work provides a new strategy for the transition metal oxides modification of Au-based catalysts,which would be constructive for the rational design of other heterogeneous catalysts.展开更多
基金We gratefully acknowledge the financially support by the National Natural Science Foundation of China （Nos. 21631007, 21401050, 21471087 and 21271068）, Beijing Natural Science Foundation （No. 2164063）, China Postdoctoral Science Foundation （No. 2014M560948）, the State Key Laboratory of Natural and Biomimetic Drugs （No. K20160202）, the National Natural Science Foundation of Hubei Province （No. 2015CFA131） and Wuhan Applied Basic Research Program （No. 2014010101010020）. T. B. L. acknowledges support from the National Science Foundation （No. CHE1607138） and the University of Akron.
文摘An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer vesicles formed from a hexavanadate cluster functionalized with two alkyl chains are highly efficient catalysts for the oxidation of 3,3＇,5,5＇-tetramethylbenzidine （TMB） with H2O2 at room temperature, a widely used model reaction mimicking the activity of peroxidase in biological catalytic oxidation processes. Driven by hydrophobic interactions, the double-tailed hexavanadate-headed amphiphiles can self-assemble into bilayer vesicles and create hydrophobic domains that segregate the TMB chromogenic substrate. The reaction of TMB with H2O2 takes place at the interface of the hydrophilic and hydrophobic domains, where the reagents also make contact with the catalytic hexavanadate clusters, and it is approximately two times more efficient compared with the reactions carried out with the corresponding unassembled systems. Moreover, the assembled vesicular system possesses affinity for TMB comparable to that of reported noble metal mimic nanomaterials, as well as a higher maximum reaction rate.
基金National Natural Science Foundation of China,21773212,Zhenhua ZhangJinhua Industrial Key Project,20221080,Zhenhua Zhangself-designed scientific research project of Zhejiang Normal University,2021ZS0602,Zhenhua Zhang.
文摘Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil energies,while such a process is limited by chemical inertia and thermal stability of the CO_(2) molecule and complex hydrogenation routes.In this review,we first summarized the recent progresses of metal-oxide nanocatalysts considered as a category of the most promising catalysts in CO_(2) hydrogenation to value-added C1 chemicals including CH_(4)/CO,formic acid/formate,and methanol.These studies involve with different structural factors affecting the metal-oxide interfacial catalysis including the structures of both the metals(type,particle size,morphology/crystal plane,and bimetal alloy)and the supports(type,particle size,crystal phase,morphology/crystal plane,and composite)and their(strong)metal-support interactions so as to identify the key factor determining the reaction activity,product selectivity,and catalytic stability in CO_(2) hydrogenation.Finally,we further discuss challenging coupling with future research opportunities for tunable interfacial catalysis of metal-oxide nanocatalysts in CO_(2) conversion.
基金support of State Key Laboratory of Chemical Engineering (No.SKL-ChE-20A02)the support of International Clean Energy Talent Program by China Scholarship Council.
文摘Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural(HMF)oxidation,promoting the catalytic performance at low loading amounts still remains a significant challenge.Herein,a series of metal oxide modified MO_(x)-Au/TiO_(2)(M=Fe,Co,Ni)catalysts with low Au loading amount of 0.5 wt%were synthesized.Addition of transition metal oxides promotes electron transfer and generation of the Au^(δ-)-O_(v)-Ti^(3+)interface.A combination study reveals that the dual-active site(Au^(δ-)-O_(v)-Ti^(3+))governs the catalytic performance of the ratedetermining step,namely hydroxyl group oxidation.Au^(δ-) site facilitates chemisorption and activation of O_(2) molecules.At the same time,O_(v)-Ti^(3+) site acts as the role of“killing two birds with one stone”:enhancing adsorption of both reactants,accelerating the activation and dissociation of H_(2)O,and facilitating activation of the adsorbed O_(2).Besides,superoxide radicals instead of base is the active oxygen species during the rate-determining step.On this basis,a FDCA yield of 71.2% was achieved under base-free conditions,complying with the“green chemistry”principle.This work provides a new strategy for the transition metal oxides modification of Au-based catalysts,which would be constructive for the rational design of other heterogeneous catalysts.
