Deciphering dynamic surface of PtRu alloy nanocatalysts to revisit their synergistic effects during the electrooxidation  

作　　者：Xiao-Chong Li Bo Wang Zhou Yu Qiang Wan Ju-Fang Zheng Emmanuel Maisonhaute Xiao-Shun Zhou Ya-Hao Wang 

机构地区：[1]Key Laboratory of the Ministry of Education for Advanced Catalysis Materials,Institute of Physical Chemistry,Zhejiang Normal University,Jinhua 321004,China [2]Laboratoire Interface et Systèmes Electrochimiques,CNRS UMR 8235,Sorbonne Université,F-75252 Paris cedex 5,France

出　　处：《Science China Chemistry》2024年第7期2224-2233,共10页中国科学（化学英文版）

基　　金：supported by the Zhejiang Provincial Natural Science Foundation of China(LQ21B030010 and LQ24B030014);the National Natural Science Foundation of China(22102150,22172146,22303085,21872126 and 21573198)。

摘　　要：Correlating dynamic structural transformation of catalysts with the surface intermediate species under operating conditions is critical for updating the understanding of structure–performance relationships.Here,we probe the electrochemical potentialdependent surface structures and adsorbed intermediates on PtRu binary alloy nanocatalysts to revisit its synergistic mechanisms for CO electrooxidation enhanced activity.In-situ spectral characteristics by using modified shell-isolated nanoparticle-enhanced Raman spectroscopy,show that in acidic solution,when the potential is positively scanned from 0.1 V to 1.5 V relative to reversible hydrogen electrode(RHE),the surface of the alloy catalyst evolves from metallic PtRu to adsorbed oxygen gradually covering and accumulating on Ru sites(denoted as PtRuO_(x),x≤2),forming segregated RuO_(2),and finally forming a threedimensional oxide layer(denoted as 3D PtRuO_(4)).Moreover,molecular evidence associated with periodic density functional theory calculations reveals that electronic effects promote ruthenium to become more oxidizable and oxophilic.In particular,we found here that ^(*)O and ^(*)OH at surface RuO_(x) sites are highly efficient CO oxidation active species in comparison to the same entities adsorbed on metallic Ru sites.This work sheds light on the complex surface dynamic process of practical Pt-based binary nanocatalysts and improves the understanding of synergistic mechanism for the development of fuel cell devices.

关 键 词：in-situ Raman spectroscopy surface evolution bifunctional mechanism PTRU ELECTROOXIDATION 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TQ426[化学工程] TB383.1[一般工业技术—材料科学与工程]