Molecular oxygen within Polyoxometalates(POMs)based compounds are ideal oxidants with high atom economy and its use results in the production of water as the only byproduct.Significant progress has been made in the de...Molecular oxygen within Polyoxometalates(POMs)based compounds are ideal oxidants with high atom economy and its use results in the production of water as the only byproduct.Significant progress has been made in the development of catalytic methods for aerobic alcohol oxidation to have aldehydes and ketones with POMs based compounds.They are alternative to the use of traditional hypervalent iodine catalyst systems which are with molecular oxygen as a terminal oxidant.Further,POMs based catalysts can be applied to catalytic reactions with different modes of energization such as thermocatalysis,photocatalysis and electrocatalysis.This review summarizes the frontier advances in polyoxometalates for catalytic alcohol selective oxidation in thermocatalytic,electrocatalytic,and photocatalytic applications.The three advantages of POM catalysts in terms of performance,economy,and environmental protection are highlighted.These include the use of sol-gel and electrostatic assembly methods to increase the reaction surface area,reduce the use of precious metals,and improve the stability of POMs catalysts.The field of selective alcohol oxidation is advanced.Finally,the challenges of preparing more efficient and“green”catalysts are presented.展开更多
Electroreduction of greenhouse gas CO_(2) into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change.However,the regulations of the selectivity to...Electroreduction of greenhouse gas CO_(2) into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change.However,the regulations of the selectivity towards C2 product and the competing hydrogen evolution reaction(HER)are major challenges for CO_(2) reduction reaction(CO_(2)RR).Here,we develop an interface-enhanced strategy by depositing a thin layer of nitrogen-doped graphene(N-G)on a Cu foam surface(Cu-N-G)to selectively promote the ethanol pathway in CO_(2)RR.Compared to the undetectable ethanol selectivity of pure Cu and Cu@graphene(Cu-G),Cu-N-G has boosted the ethanol selectivity to 33.1%in total Faradic efficiency(FE)at−0.8 V vs.reversible hydrogen electrode(RHE).The experimental and density functional theory(DFT)results verify that the interconnected graphene coating can not only serve as the fast charge transport channel but also provide confined nanospace for mass transfer.The N doping can not only trigger the intrinsic interaction between N in N-G and CO_(2) molecule for enriching the local concentration of reactants but also promote the average valence state of Cu for C–C coupling pathways.The confinement effect at the interface of Cu-N-G can not only provide high adsorbed hydrogen(Had)coverage but also stabilize the key*HCCHOH intermediate towards ethanol pathway.The provided interface-enhanced strategy herein is expected to inspire the design of Cubased CO_(2)RR electrocatalysts towards multi-carbon products.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21801153 and 21971134)Academic Promotion Program of Shandong First Medical University(No.2019LJ003).
文摘Molecular oxygen within Polyoxometalates(POMs)based compounds are ideal oxidants with high atom economy and its use results in the production of water as the only byproduct.Significant progress has been made in the development of catalytic methods for aerobic alcohol oxidation to have aldehydes and ketones with POMs based compounds.They are alternative to the use of traditional hypervalent iodine catalyst systems which are with molecular oxygen as a terminal oxidant.Further,POMs based catalysts can be applied to catalytic reactions with different modes of energization such as thermocatalysis,photocatalysis and electrocatalysis.This review summarizes the frontier advances in polyoxometalates for catalytic alcohol selective oxidation in thermocatalytic,electrocatalytic,and photocatalytic applications.The three advantages of POM catalysts in terms of performance,economy,and environmental protection are highlighted.These include the use of sol-gel and electrostatic assembly methods to increase the reaction surface area,reduce the use of precious metals,and improve the stability of POMs catalysts.The field of selective alcohol oxidation is advanced.Finally,the challenges of preparing more efficient and“green”catalysts are presented.
基金supported by the National Natural Science Foundation of China(Nos.21907043 and 21801153)Shandong Provincial Natural Science Foundation(No.ZR2019BB025).
文摘Electroreduction of greenhouse gas CO_(2) into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change.However,the regulations of the selectivity towards C2 product and the competing hydrogen evolution reaction(HER)are major challenges for CO_(2) reduction reaction(CO_(2)RR).Here,we develop an interface-enhanced strategy by depositing a thin layer of nitrogen-doped graphene(N-G)on a Cu foam surface(Cu-N-G)to selectively promote the ethanol pathway in CO_(2)RR.Compared to the undetectable ethanol selectivity of pure Cu and Cu@graphene(Cu-G),Cu-N-G has boosted the ethanol selectivity to 33.1%in total Faradic efficiency(FE)at−0.8 V vs.reversible hydrogen electrode(RHE).The experimental and density functional theory(DFT)results verify that the interconnected graphene coating can not only serve as the fast charge transport channel but also provide confined nanospace for mass transfer.The N doping can not only trigger the intrinsic interaction between N in N-G and CO_(2) molecule for enriching the local concentration of reactants but also promote the average valence state of Cu for C–C coupling pathways.The confinement effect at the interface of Cu-N-G can not only provide high adsorbed hydrogen(Had)coverage but also stabilize the key*HCCHOH intermediate towards ethanol pathway.The provided interface-enhanced strategy herein is expected to inspire the design of Cubased CO_(2)RR electrocatalysts towards multi-carbon products.
