Perovskite oxides are significant candidates to develop electrochemical catalysts for water oxidation in consideration of their high catalysis capacity,low costing and excellent stability.Rational design of coordinati...Perovskite oxides are significant candidates to develop electrochemical catalysts for water oxidation in consideration of their high catalysis capacity,low costing and excellent stability.Rational design of coordination structure and overcoming poor electronic transport are regarded as critical factors for outstanding perovskite-based oxygen evolution reaction (OER) catalysts.Herein,we report a mild chemical oxidation method to realize ligancy engineering from strongly-correlated brownmillerite Sr2Co2O5 to perovskite phase Sr2Co2O5.5,along with abundant oxygen vacancies formation and greatly boosted electric conductivity,which helps to form the active species of Co hydroxide/oxide on the surface of catalysts.The coupling effect of catalytic kinetics and unimpeded electronic movement brings high OER activities in Sr2Co2O5.5 with a low onset potential and a small Tafel slope.Our work not only displays in-depth understanding into the relationship among catalysis performance and multiple physical degrees of freedom,but also paves a new path to develop high-efficient electrochemical catalysts.展开更多
基金This work was financially supported by the National Key R&D Program of Chnia(No.2017YFA0207301)the National Natural Science Foundation of China(Nos.U1632154,21890751,91745113,11621063,21601172,and J1030412)+2 种基金National Program for Support of Top-notch Young Professionals,the Fundamental Research Funds for the Central Universities(No.WK2090050043)Youth Innovation Promotion Association of CAS(No.2018500)Users with Excellence Project of Hefei Science Center(No.CAS2018HSCUE002).
文摘Perovskite oxides are significant candidates to develop electrochemical catalysts for water oxidation in consideration of their high catalysis capacity,low costing and excellent stability.Rational design of coordination structure and overcoming poor electronic transport are regarded as critical factors for outstanding perovskite-based oxygen evolution reaction (OER) catalysts.Herein,we report a mild chemical oxidation method to realize ligancy engineering from strongly-correlated brownmillerite Sr2Co2O5 to perovskite phase Sr2Co2O5.5,along with abundant oxygen vacancies formation and greatly boosted electric conductivity,which helps to form the active species of Co hydroxide/oxide on the surface of catalysts.The coupling effect of catalytic kinetics and unimpeded electronic movement brings high OER activities in Sr2Co2O5.5 with a low onset potential and a small Tafel slope.Our work not only displays in-depth understanding into the relationship among catalysis performance and multiple physical degrees of freedom,but also paves a new path to develop high-efficient electrochemical catalysts.
