Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures a...Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.展开更多
Heteroatom-doped Pt-based nanocrystals have generated considerable interest and hold great prospects in heterocatalysis. However, engineering the superficial atomic configurations of these nanocrystals via in situ sur...Heteroatom-doped Pt-based nanocrystals have generated considerable interest and hold great prospects in heterocatalysis. However, engineering the superficial atomic configurations of these nanocrystals via in situ surface doping remains exceedingly challenging. Herein, we propose a onepot, in situ surface doping chemical synthesis protocol to prepare quatermetallic Pt Ni Co Rh dendritic nanocrystals as versatile and active catalysts for the electrooxidation of C_(1) fuels. Leveraging the selective coordination effect between ascorbic acid and Rh^(3+)ions, the doping of trace Rh atoms can be guided specifically at the near-surface of Pt Ni Co Rh nanocatalysts. Electrocatalytic tests indicate that Pt_(67)Ni_(16)Co_(16)Rh_(1) nanocrystals with in situ trace Rh-doped surface exhibit substantially enhanced activity, durability, and CO tolerance for the electrooxidation of methanol, formaldehyde, and formic acid. In situ Fourier transform infrared spectroscopy provides molecular-level insight into the exceptional performance of these nanocatalysts. The surface incorporation of anticorrosive Rh atoms enables the transfer of CO intermediates from the atop Pt sites to the bridged Rh–Pt surface sites,thereby facilitating the elimination of these poisoning species from the catalyst surface. This study presents an effective in situ surface doping strategy which can enable the design of more atom-economic heterocatalysts.展开更多
文摘Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.
基金supported by the National Natural Science Foundation of China (21771067)the Natural Science Foundation of Fujian Province (2017J06005 and 2019J01058)+3 种基金the Program for New Century Excellent Talents in Fujian Province Universitythe Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University (ZQN-PY507)the Scientific Research Funds of Huaqiao Universitythe Instrumental Analysis Center of Huaqiao University for the analysis support。
文摘Heteroatom-doped Pt-based nanocrystals have generated considerable interest and hold great prospects in heterocatalysis. However, engineering the superficial atomic configurations of these nanocrystals via in situ surface doping remains exceedingly challenging. Herein, we propose a onepot, in situ surface doping chemical synthesis protocol to prepare quatermetallic Pt Ni Co Rh dendritic nanocrystals as versatile and active catalysts for the electrooxidation of C_(1) fuels. Leveraging the selective coordination effect between ascorbic acid and Rh^(3+)ions, the doping of trace Rh atoms can be guided specifically at the near-surface of Pt Ni Co Rh nanocatalysts. Electrocatalytic tests indicate that Pt_(67)Ni_(16)Co_(16)Rh_(1) nanocrystals with in situ trace Rh-doped surface exhibit substantially enhanced activity, durability, and CO tolerance for the electrooxidation of methanol, formaldehyde, and formic acid. In situ Fourier transform infrared spectroscopy provides molecular-level insight into the exceptional performance of these nanocatalysts. The surface incorporation of anticorrosive Rh atoms enables the transfer of CO intermediates from the atop Pt sites to the bridged Rh–Pt surface sites,thereby facilitating the elimination of these poisoning species from the catalyst surface. This study presents an effective in situ surface doping strategy which can enable the design of more atom-economic heterocatalysts.
