Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm thr...Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm through experimental results that Bi-based catalysts containing halogen ions(I^(-),Cl^(-),Br^(-))and SO_(4)^(2-)maintain the system stability,keeping Faraday efficiency of formic acid above90%in the current range of 50-800 mA cm^(-2).In contrast,anions containing S^(2-)and NO_(3)^(-)in the electrolyte can be reduced to produce by-products.These anions and their by-products could poison the active center,leading to increased side reactions and thus significantly reducing the Faraday efficiency of formic acid.The combination of non-in situ and in situ characterization results revealed that the Bi-based catalysts all underwent the transition from the initial state to the Bi/Bi_(2)O_(2)CO_(3)(BOC)intermediate state in high-concentration KHCO_(3) solution,and the different anions could selectively modulate the degree of exposure of specific crystalline surfaces of BOC.At the late stage of the reaction,BOC was completely converted to metal Bi and became the real active center.Combined with in situ IR and DFT calculations,it is further verified that^(*)OCHO is the key intermediate on the metallic Bi surface,which is most favorable for formic acid formation.This study reveals the key mechanism by which anions affect the formation of active sites via modulating the catalyst reconstruction process,which provides an important theoretical basis for the design and optimization of test conditions of Bi-based catalysts.展开更多
Copper(Cu)-based catalysts show significant potential for producing high value-added C_(2+)products in electrocatalytic CO_(2)/CO reduction reactions(CO(2)RR).However,the structural reconfiguration during operation po...Copper(Cu)-based catalysts show significant potential for producing high value-added C_(2+)products in electrocatalytic CO_(2)/CO reduction reactions(CO(2)RR).However,the structural reconfiguration during operation poses substantial challenges in identifying the intrinsic catalytic active site,especially under similar mass transport conditions.Herein,three typical and commercial Cu-based catalysts(Cu,CuO,and Cu_(2)O)are chosen as representatives to elucidate the structure-activity relationship of CORR in the membrane electrode assembly electrolyzer.Notably,only the Cu catalyst demonstrates the most suppression of hydrogen evolution reaction,thus achieving the highest FE of 86.7% for C_(2+)products at a current density of 500 mA cm^(-2) and maintaining a stable electrolysis over 110 h at a current of 200 mA cm^(-2).The influence of chemical valence state of Cu,electrochemical surface area,and local pH were firstly investigated and ruled out for the significant FE differences.Finally,based on the structure analysis from high resolution transmission electron microscope,OH-adsorption,in situ infrared spectroscopy and density functional theory calculations,it is suggested that the asymmetric C-C coupling(via ^(*)CHO and ^(*)CO)is the most probable reaction pathway for forming C_(2+)products,with Cu(100)-dominant grain boundaries(GBs)being the most favorable active sites.These findings provide deeper insights into the synergistic relationship between crystal facets and GBs in electrocatalytic systems.展开更多
Diatomic-site catalysts(DASCs)have emerged as a kind of promising heterogeneous candidate catalysts for electrochemical CO_(2)reduction(ECR),which is considered to retain the advantage of single-atom catalysts(SACs)bu...Diatomic-site catalysts(DASCs)have emerged as a kind of promising heterogeneous candidate catalysts for electrochemical CO_(2)reduction(ECR),which is considered to retain the advantage of single-atom catalysts(SACs)but also introduce opportunities to exceed the limit of single-atom catalysts.In the past few years,tremendous progress has been achieved in this field.Herein,the recent progress in ECR on DASCs has been summarized.It will start with the classification of DASCs.Then the challenges in the precise fabrication and characterization of DASCs have been emphasized.By introducing the advanced ECR performance on DASCs,superior to that on SACs,the synergistic effects of the dual metal atoms are highlighted,as this origin of the advanced ECR performance on DASCs is comprehensively summarized.Finally,the major challenges and perspectives of DASCs have been proposed to shed light on the development of DASCs for ECR application.展开更多
Crystal defect is well-known to have a significant effect on the photocatalytic performance of semiconductors. Herein, defect-rich and-poor BaSn(OH)6(BSOH-Sn and BSOH-Ba) photocatalysts were synthesized by exchanging ...Crystal defect is well-known to have a significant effect on the photocatalytic performance of semiconductors. Herein, defect-rich and-poor BaSn(OH)6(BSOH-Sn and BSOH-Ba) photocatalysts were synthesized by exchanging the addition order of Ba and Sn. Results show that the defect-poor BSOH-Ba exhibited more efficient toluene degradation under ultraviolet(UV) light, which could attribute to the great suppression of photogenerated electron-hole(e--h+) pairs recombination by tuning the defect concentration. The low defect concentration in BSOH-Ba finally promotes the charge separation efficiency, the generation of reactive oxygen species(ROS), and the photocatalytic toluene degradation reactions. This work not only provides an effective way to inhibit the recombination of photogenerated carriers and improve the photocatalytic performance, but also promotes the understanding of defective perovskite-type hydroxide for more photoreactions.展开更多
Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavora...Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavorable interface that largely determines the reaction efficiency and selectivity.Here we present an in situ dynamic reconstruction strategy to enhance the NO_(3)^(-)RR by constructing Cu/Ce(OH)_(x)catalyst with abundant interfacial active sites.The Cu/Ce(OH)_(x)catalyst was in situ formed through dynamic reconstruction of Cu_(2)Cl(OH)_(3)/Ce(OH)_(x)heterostructure during electrochemical NO_(3)^(‒)RR process.The catalyst exhibits high performance with NO_(3)^(-)conversion of 100.0%,NH_(3)selectivity of 97.8%,NH_(3)Faradaic efficiency of 99.2%and long stability,which is among the state-of-the-art catalysts in neutral media.Both experimental and theoretical results demonstrate that the Cu and Ce sites at the interface can operate cooperatively to promote the adsorption and activation of NO_(3)^(-),and lower the formation energy of key intermediate*HNO.Meanwhile,the hydrogen evolution reaction is also greatly suppressed due to the high H*binding strength at the interface.The strategy can be extended to other catalytic systems and opens a new avenue for the design of efficient electrocatalysts.展开更多
Electrocatalytic CO_(2) reduction at mild conditions is a promising strategy to transform greenhouse gases into fuels or value-added chemicals to solve the increasingly serious environmental and energy problems.The mo...Electrocatalytic CO_(2) reduction at mild conditions is a promising strategy to transform greenhouse gases into fuels or value-added chemicals to solve the increasingly serious environmental and energy problems.The most crucial factor in determining the CO_(2) reduction performance is to develop efficient electrocatalysts with high selectivity and stability.Among the various electrocatalysts,indium-based catalysts have attracted extensive attention due to their non-toxicity,low cost,and high formic acid/formate selectivity.In this work,we comprehensively review the recent development and research progress of indium-based electrocatalysts for CO_(2)RR.The reaction mechanism,reaction pathways,structure-activity relationship,and strategies to enhance the activity of CO_(2)RR on indium-based catalysts have also been briefly presented and discussed.Finally,the existing challenges and future developments for indium-based highperformance catalysts for CO_(2)RR are proposed.展开更多
To date,copper-based catalysts are one of the most prominent catalysts that can electrochemically reduce CO_(2)towards highvalue fuels or chemicals,such as ethylene,ethanol,and acetic acid.However,the chemically activ...To date,copper-based catalysts are one of the most prominent catalysts that can electrochemically reduce CO_(2)towards highvalue fuels or chemicals,such as ethylene,ethanol,and acetic acid.However,the chemically active feature of Cu-based catalysts hinders the understanding of the intrinsic catalytic active sites during the initial and the operative processes of electrochemical CO_(2)reduction(CO_(2)RR).The identification and engineering of active sites during the dynamic evolution of catalysts are thereby vital to further improve the activity,selectivity,and durability of Cu-based catalysts for high-performance CO_(2)RR.In this regard,four triggers for the dynamic evolution of catalysts were introduced in detail.Afterward,three typical active-site theories during the dynamic reconstruction of catalysts were discussed.In addition,the strategies in catalyst design were summarized according to the latest reports of Cu-based catalysts for CO_(2)RR,including the tuning of electronic structure,controlling of the external potential,and regulation of local catalytic environment.Finally,the conclusions and perspectives were provided to inspire more investigations and studies on the intrinsic active sites during the dynamic evolution of catalysts,which could promote the optimization of the catalyst system to further improve the performance of CO_(2)RR.展开更多
基金funded by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C03017)China Postdoctoral Science Foundation(No.GZC20230373)+5 种基金Zhejiang Provincial Natural Science Foundation of China(No.LQ24B070010)CMA Key Open Laboratory of Transforming Climate Resources to Economy(No.2024004K)Natural Science Foundation of Huzhou City(No.2024YZ19)the National Natural Science Foundation of China(Nos.22202032,22406020 and 22406019)the Key Research and Development Projects of Xinjiang Uygur Autonomous Region,China(No.2022B02031)Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(No.LBMHY25E060009)。
文摘Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm through experimental results that Bi-based catalysts containing halogen ions(I^(-),Cl^(-),Br^(-))and SO_(4)^(2-)maintain the system stability,keeping Faraday efficiency of formic acid above90%in the current range of 50-800 mA cm^(-2).In contrast,anions containing S^(2-)and NO_(3)^(-)in the electrolyte can be reduced to produce by-products.These anions and their by-products could poison the active center,leading to increased side reactions and thus significantly reducing the Faraday efficiency of formic acid.The combination of non-in situ and in situ characterization results revealed that the Bi-based catalysts all underwent the transition from the initial state to the Bi/Bi_(2)O_(2)CO_(3)(BOC)intermediate state in high-concentration KHCO_(3) solution,and the different anions could selectively modulate the degree of exposure of specific crystalline surfaces of BOC.At the late stage of the reaction,BOC was completely converted to metal Bi and became the real active center.Combined with in situ IR and DFT calculations,it is further verified that^(*)OCHO is the key intermediate on the metallic Bi surface,which is most favorable for formic acid formation.This study reveals the key mechanism by which anions affect the formation of active sites via modulating the catalyst reconstruction process,which provides an important theoretical basis for the design and optimization of test conditions of Bi-based catalysts.
文摘Copper(Cu)-based catalysts show significant potential for producing high value-added C_(2+)products in electrocatalytic CO_(2)/CO reduction reactions(CO(2)RR).However,the structural reconfiguration during operation poses substantial challenges in identifying the intrinsic catalytic active site,especially under similar mass transport conditions.Herein,three typical and commercial Cu-based catalysts(Cu,CuO,and Cu_(2)O)are chosen as representatives to elucidate the structure-activity relationship of CORR in the membrane electrode assembly electrolyzer.Notably,only the Cu catalyst demonstrates the most suppression of hydrogen evolution reaction,thus achieving the highest FE of 86.7% for C_(2+)products at a current density of 500 mA cm^(-2) and maintaining a stable electrolysis over 110 h at a current of 200 mA cm^(-2).The influence of chemical valence state of Cu,electrochemical surface area,and local pH were firstly investigated and ruled out for the significant FE differences.Finally,based on the structure analysis from high resolution transmission electron microscope,OH-adsorption,in situ infrared spectroscopy and density functional theory calculations,it is suggested that the asymmetric C-C coupling(via ^(*)CHO and ^(*)CO)is the most probable reaction pathway for forming C_(2+)products,with Cu(100)-dominant grain boundaries(GBs)being the most favorable active sites.These findings provide deeper insights into the synergistic relationship between crystal facets and GBs in electrocatalytic systems.
基金supported by“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C03017)National Natural Science Foundation of China(Nos.22225606,22261142663,and 22176029)+1 种基金China Postdoctoral Science Foundation(No.2023M730491)Natural Science Foundation of Huzhou City(No.2022YZ22)。
文摘Diatomic-site catalysts(DASCs)have emerged as a kind of promising heterogeneous candidate catalysts for electrochemical CO_(2)reduction(ECR),which is considered to retain the advantage of single-atom catalysts(SACs)but also introduce opportunities to exceed the limit of single-atom catalysts.In the past few years,tremendous progress has been achieved in this field.Herein,the recent progress in ECR on DASCs has been summarized.It will start with the classification of DASCs.Then the challenges in the precise fabrication and characterization of DASCs have been emphasized.By introducing the advanced ECR performance on DASCs,superior to that on SACs,the synergistic effects of the dual metal atoms are highlighted,as this origin of the advanced ECR performance on DASCs is comprehensively summarized.Finally,the major challenges and perspectives of DASCs have been proposed to shed light on the development of DASCs for ECR application.
基金supported by the National Natural Science Foundation of China (Nos. 22176029, 21822601, 51908091, and 52200122)the Natural Science Foundation of Chongqing (No. cstc2019jcyj-msxm X0213)+1 种基金the Science and Technology Research Project of Chongqing Education Commission (No. KJQN202200806)the Start-up Foundation of High-level Talents in Chongqing Technology and Business University (Nos. 2256006 and 1856044)。
文摘Crystal defect is well-known to have a significant effect on the photocatalytic performance of semiconductors. Herein, defect-rich and-poor BaSn(OH)6(BSOH-Sn and BSOH-Ba) photocatalysts were synthesized by exchanging the addition order of Ba and Sn. Results show that the defect-poor BSOH-Ba exhibited more efficient toluene degradation under ultraviolet(UV) light, which could attribute to the great suppression of photogenerated electron-hole(e--h+) pairs recombination by tuning the defect concentration. The low defect concentration in BSOH-Ba finally promotes the charge separation efficiency, the generation of reactive oxygen species(ROS), and the photocatalytic toluene degradation reactions. This work not only provides an effective way to inhibit the recombination of photogenerated carriers and improve the photocatalytic performance, but also promotes the understanding of defective perovskite-type hydroxide for more photoreactions.
文摘Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavorable interface that largely determines the reaction efficiency and selectivity.Here we present an in situ dynamic reconstruction strategy to enhance the NO_(3)^(-)RR by constructing Cu/Ce(OH)_(x)catalyst with abundant interfacial active sites.The Cu/Ce(OH)_(x)catalyst was in situ formed through dynamic reconstruction of Cu_(2)Cl(OH)_(3)/Ce(OH)_(x)heterostructure during electrochemical NO_(3)^(‒)RR process.The catalyst exhibits high performance with NO_(3)^(-)conversion of 100.0%,NH_(3)selectivity of 97.8%,NH_(3)Faradaic efficiency of 99.2%and long stability,which is among the state-of-the-art catalysts in neutral media.Both experimental and theoretical results demonstrate that the Cu and Ce sites at the interface can operate cooperatively to promote the adsorption and activation of NO_(3)^(-),and lower the formation energy of key intermediate*HNO.Meanwhile,the hydrogen evolution reaction is also greatly suppressed due to the high H*binding strength at the interface.The strategy can be extended to other catalytic systems and opens a new avenue for the design of efficient electrocatalysts.
基金supported by National Science Foundation of China(Nos.22225606,22261142663 and 22176029)the Excellent Youth Foundation of Sichuan Scientific Committee(No.2021JDJQ0006)。
文摘Electrocatalytic CO_(2) reduction at mild conditions is a promising strategy to transform greenhouse gases into fuels or value-added chemicals to solve the increasingly serious environmental and energy problems.The most crucial factor in determining the CO_(2) reduction performance is to develop efficient electrocatalysts with high selectivity and stability.Among the various electrocatalysts,indium-based catalysts have attracted extensive attention due to their non-toxicity,low cost,and high formic acid/formate selectivity.In this work,we comprehensively review the recent development and research progress of indium-based electrocatalysts for CO_(2)RR.The reaction mechanism,reaction pathways,structure-activity relationship,and strategies to enhance the activity of CO_(2)RR on indium-based catalysts have also been briefly presented and discussed.Finally,the existing challenges and future developments for indium-based highperformance catalysts for CO_(2)RR are proposed.
基金supported by the“Pioneer”and“Leading Goose”R&D Programs of Zhejiang(2022C03146)National Natural Science Foundation of China(22225606 and 22176029)Central Government Guided Local Science and Technology Development Fund(2021ZY1022)。
文摘To date,copper-based catalysts are one of the most prominent catalysts that can electrochemically reduce CO_(2)towards highvalue fuels or chemicals,such as ethylene,ethanol,and acetic acid.However,the chemically active feature of Cu-based catalysts hinders the understanding of the intrinsic catalytic active sites during the initial and the operative processes of electrochemical CO_(2)reduction(CO_(2)RR).The identification and engineering of active sites during the dynamic evolution of catalysts are thereby vital to further improve the activity,selectivity,and durability of Cu-based catalysts for high-performance CO_(2)RR.In this regard,four triggers for the dynamic evolution of catalysts were introduced in detail.Afterward,three typical active-site theories during the dynamic reconstruction of catalysts were discussed.In addition,the strategies in catalyst design were summarized according to the latest reports of Cu-based catalysts for CO_(2)RR,including the tuning of electronic structure,controlling of the external potential,and regulation of local catalytic environment.Finally,the conclusions and perspectives were provided to inspire more investigations and studies on the intrinsic active sites during the dynamic evolution of catalysts,which could promote the optimization of the catalyst system to further improve the performance of CO_(2)RR.
