The development of high-performance Ir-based catalyst for electrocatalysis of oxygen evolution reaction(OER)in acidic media plays a critical role in realizing the commercialization of polymer electrolyte membrane-base...The development of high-performance Ir-based catalyst for electrocatalysis of oxygen evolution reaction(OER)in acidic media plays a critical role in realizing the commercialization of polymer electrolyte membrane-based water electrolyzer technology.Here we report a low-Ir core–shell OER electrocatalyst consisting of an intermetallic IrGa(IrGa-IMC)core and a partially oxidized Ir(IrOx)shell.In acidic electrolytes,the IrGa-IMC@IrOx core–shell catalysts exhibit a low overpotential of 272 mV at 10 mA·cm^(−2) with Ir loading of~20µg·cm^(−2) and a mass activity of 841 A·gIr^(−1) at 1.52 V,which is 3.6 times greater than that of commercial Ir/C(232 A·gIr^(−1))catalyst.We understand by the density functional theory(DFT)calculations that the enhanced OER activity of the IrGa-IMC@IrO_(x) catalysts is ascribed to the lifted degeneracy of Ir 5d electron of surface IrO_(x) sites induced by the intermetallic IrGa core,which increases the adsorption capacity of IrO_(x) layer for O and OH binding and eventually lowers the energy barrier of the OER rate-determining steps.展开更多
基金the National Key Research and Development Program of China(No.2018YFA0702001)the National Natural Science Foundation of China(Nos.22071225 and 11774327)+2 种基金the Fundamental Research Funds for the Central Universities(No.WK2060190103)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(No.KY2060000175)the support by“the Recruitment Program of Thousand Youth Talents”.
文摘The development of high-performance Ir-based catalyst for electrocatalysis of oxygen evolution reaction(OER)in acidic media plays a critical role in realizing the commercialization of polymer electrolyte membrane-based water electrolyzer technology.Here we report a low-Ir core–shell OER electrocatalyst consisting of an intermetallic IrGa(IrGa-IMC)core and a partially oxidized Ir(IrOx)shell.In acidic electrolytes,the IrGa-IMC@IrOx core–shell catalysts exhibit a low overpotential of 272 mV at 10 mA·cm^(−2) with Ir loading of~20µg·cm^(−2) and a mass activity of 841 A·gIr^(−1) at 1.52 V,which is 3.6 times greater than that of commercial Ir/C(232 A·gIr^(−1))catalyst.We understand by the density functional theory(DFT)calculations that the enhanced OER activity of the IrGa-IMC@IrO_(x) catalysts is ascribed to the lifted degeneracy of Ir 5d electron of surface IrO_(x) sites induced by the intermetallic IrGa core,which increases the adsorption capacity of IrO_(x) layer for O and OH binding and eventually lowers the energy barrier of the OER rate-determining steps.
