The alkaline hydrogen evolution reaction(HER)on Pt-based catalysts is largely limited by the slow water dissociation kinetics.Pt-based single atom alloy catalysts(SAAC)with water dissociation sites have been demonstrated as excellent alkaline HER catalysts.However,the regulation of their activity and stability at the atomic scale is still a great challenge.Herein,the kinetic and stability issues are successfully resolved via engineering the electronic structure of Pt-Co SAAC by Au-induced tensile strain.The atomic dispersion of Co into the Pt shell was confirmed by extended X-ray absorption fine structure and the electronic structure and catalytic HER performance was modulated by the tensile strain induced by the Pt shell thickness.An inverse volcano-type relation between HER activity and surface strain was found.Density functional theory(DFT)calculations reveal that the Au-induced tensile strain on Pt-Co shell can not only boost the adsorption and dissociation kinetics of water at Co site by upshifting the d-band and promoting the electron transfer,but also downshift the d-band center of Pt in Pt-Co shell,lead-ing to optimized H* adsorption/desorption.The champion catalyst provides an overpotential of only 14 mV at the current density of 10 mA cm-2.This work not only provides an effective strategy for the construction of single-atom alloy electrocatalysts for high performance toward alkaline HER but also sheds light on the understanding of the reaction mechanism at the atomic level.

Rendian Wan;Mi Luo;Jingbo Wen;Shilong Liu;Xiongwu Kang;Yong Tian

School of Pharmacy,Guangdong Pharmaceutical University,Guangzhou 510006,Guangdong,China;New Energy Research Institute,School of Environment and Energy,South China University of Technology,Higher Education Mega Center,Guangzhou 510006,Guangdong,China

能源化学

[1]Rendian Wan;Mi Luo;Jingbo Wen;Shilong Liu;Xiongwu Kang;Yong Tian-.Pt-Co single atom alloy catalysts:Accelerated water dissociation and hydrogen evolution by strain regulation)[J].能源化学,2022(06):44-53

SAAC,upshifting

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