Indium oxide(In_(2)O_(3)),as a promising candidate for CO_(2)hydrogenation to C_(1) products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction con...Indium oxide(In_(2)O_(3)),as a promising candidate for CO_(2)hydrogenation to C_(1) products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction conditions.Based on the comprehension of the dynamic evolution,this study presents an efficient strategy to alleviate the agglomeration of In_(2)O_(3)nanoparticles by the surface decoration with highly dispersed silica species(SiO_(x)).Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction,while the enhanced stability originated from the anchoring effect of highly stable In-OSi bonds,which hinders the substantial formation of metallic In(In^(0))and the subsequent agglomeration.0.6Si/In_(2)O_(3)exhibited CO_(2)conversion rate of10.0 mmol g^(-1)h^(-1)at steady state vs.3.5 mmol g^(-1)h^(-1)on In_(2)O_(3)in CO_(2)hydrogenation.Enhanced steady-state activity was also achieved on Pd-modified catalysts.Compared to the traditional Pd/In_(2)O_(3)catalyst,the methanol production rate of Pd catalyst supported on 0.6Si/In_(2)O_(3)was enhanced by 23%,showing the potential of In_(2)O_(3)modified by SiO_(x)in serving as a platform material.This work provides a promising method to design new In_(2)O_(3)-based catalysts with improved activity and stability in CO_(2)hydrogenation.展开更多
Two-dimensional(2D) transition metal dichalcogenides(TMDs) have emerged as promising alternatives to the platinum-based catalysts for hydrogen evolution reaction(HER). The edge site of these2D materials exhibits HER-a...Two-dimensional(2D) transition metal dichalcogenides(TMDs) have emerged as promising alternatives to the platinum-based catalysts for hydrogen evolution reaction(HER). The edge site of these2D materials exhibits HER-active properties, whereas the large-area basal plane is inactive.Therefore, recent studies and methodologies have been investigated to improve the performance of TMD-based materials by activating inactive sites through elemental doping strategies. In this review,we focus on the metal and non-metal dopant effects on group VI TMDs such as MoS_(2) MoSe_(2) WS_(2)and WSe_(2) for promoting HER performances in acidic electrolytes. A general introduction to the HER is initially provided to explain the parameters in accessing the catalytic performance of dopedTMDs. Then, synthetic methods for doped-TMDs and their HER performances are introduced in order to understand the effect of various dopants including metallic and non-metallic elements. Finally, the current challenges and future opportunities are summarized to provide insights into developing highly active and stable doped-TMD materials and valuable guidelines for engineering TMD-based nanocatalysts for practical water splitting technologies.展开更多
Selective coupling of methyl radicals to produce C_(2) species(C2H4 and C2H6)is a key challenge for oxidative coupling of methane(OCM).In traditional OCM reaction systems,homogeneous transformation of methyl radicals ...Selective coupling of methyl radicals to produce C_(2) species(C2H4 and C2H6)is a key challenge for oxidative coupling of methane(OCM).In traditional OCM reaction systems,homogeneous transformation of methyl radicals in O_(2)‐containing gases are uncontrollable,resulting in limited C_(2) selectivity and yield.Herein,we demonstrate that methyl radicals generated by La_(2)O_(3)at low reaction temperature can selectively couple on the surface of 5 wt%Na2WO4/SiO_(2).The controllable surface coupling against overoxidation barely changes the activity of La_(2)O_(3)but boosts the C_(2)selectivity by three times and achieves a C_(2)yield as high as 10.9%at bed temperature of only 570℃.Structure‐property studies suggest that Na_(2)WO_(4) nanoclusters are the active sites for methyl radical coupling.The strong CH_(3)·affinity of these sites can even endow some methane combustion catalysts with OCM activity.The findings of the surface coupling of methyl radicals open a new direction to develop OCM catalyst.The bifunctional OCM catalyst system,which composes of a methane activation center and a CH_(3)·coupling center,may deliver promising OCM performance at reaction temperatures below the ignition temperature of C2H6 and C2H4(~600℃)and is therefore more controllable,safer,and certainly more attractive as an actual process.展开更多
基金financially supported by the National Natural Science Foundation of China(22172013)the Special Project for Key Research and Development Program of Xinjiang Autonomous Region(2022B01033-3)+3 种基金the Liaoning Revitalization Talent Program(XLYC2008032 and XLYC2203126)the Fundamental Research Funds for the Central Universities(DUT22LK24,DUT22QN207 and DUT22LAB602)the CUHK Research Startup Fund(No.#4930981)financial support from Catalyst:Seeding funding(CSG-VUW2201)provided by the New Zealand Ministry of Business,Innovation and Employment and administered by the Royal Society Aparangi。
文摘Indium oxide(In_(2)O_(3)),as a promising candidate for CO_(2)hydrogenation to C_(1) products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction conditions.Based on the comprehension of the dynamic evolution,this study presents an efficient strategy to alleviate the agglomeration of In_(2)O_(3)nanoparticles by the surface decoration with highly dispersed silica species(SiO_(x)).Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction,while the enhanced stability originated from the anchoring effect of highly stable In-OSi bonds,which hinders the substantial formation of metallic In(In^(0))and the subsequent agglomeration.0.6Si/In_(2)O_(3)exhibited CO_(2)conversion rate of10.0 mmol g^(-1)h^(-1)at steady state vs.3.5 mmol g^(-1)h^(-1)on In_(2)O_(3)in CO_(2)hydrogenation.Enhanced steady-state activity was also achieved on Pd-modified catalysts.Compared to the traditional Pd/In_(2)O_(3)catalyst,the methanol production rate of Pd catalyst supported on 0.6Si/In_(2)O_(3)was enhanced by 23%,showing the potential of In_(2)O_(3)modified by SiO_(x)in serving as a platform material.This work provides a promising method to design new In_(2)O_(3)-based catalysts with improved activity and stability in CO_(2)hydrogenation.
基金supported by the National Research Foundation of Korea(NRF-2021R1A2C4001411,2020R1A4A1018393,2020R1C1C 1008514,2020R1I1A1A01072100,2019R1A6A1A11053838)。
文摘Two-dimensional(2D) transition metal dichalcogenides(TMDs) have emerged as promising alternatives to the platinum-based catalysts for hydrogen evolution reaction(HER). The edge site of these2D materials exhibits HER-active properties, whereas the large-area basal plane is inactive.Therefore, recent studies and methodologies have been investigated to improve the performance of TMD-based materials by activating inactive sites through elemental doping strategies. In this review,we focus on the metal and non-metal dopant effects on group VI TMDs such as MoS_(2) MoSe_(2) WS_(2)and WSe_(2) for promoting HER performances in acidic electrolytes. A general introduction to the HER is initially provided to explain the parameters in accessing the catalytic performance of dopedTMDs. Then, synthetic methods for doped-TMDs and their HER performances are introduced in order to understand the effect of various dopants including metallic and non-metallic elements. Finally, the current challenges and future opportunities are summarized to provide insights into developing highly active and stable doped-TMD materials and valuable guidelines for engineering TMD-based nanocatalysts for practical water splitting technologies.
文摘Selective coupling of methyl radicals to produce C_(2) species(C2H4 and C2H6)is a key challenge for oxidative coupling of methane(OCM).In traditional OCM reaction systems,homogeneous transformation of methyl radicals in O_(2)‐containing gases are uncontrollable,resulting in limited C_(2) selectivity and yield.Herein,we demonstrate that methyl radicals generated by La_(2)O_(3)at low reaction temperature can selectively couple on the surface of 5 wt%Na2WO4/SiO_(2).The controllable surface coupling against overoxidation barely changes the activity of La_(2)O_(3)but boosts the C_(2)selectivity by three times and achieves a C_(2)yield as high as 10.9%at bed temperature of only 570℃.Structure‐property studies suggest that Na_(2)WO_(4) nanoclusters are the active sites for methyl radical coupling.The strong CH_(3)·affinity of these sites can even endow some methane combustion catalysts with OCM activity.The findings of the surface coupling of methyl radicals open a new direction to develop OCM catalyst.The bifunctional OCM catalyst system,which composes of a methane activation center and a CH_(3)·coupling center,may deliver promising OCM performance at reaction temperatures below the ignition temperature of C2H6 and C2H4(~600℃)and is therefore more controllable,safer,and certainly more attractive as an actual process.
