Unravelling the critical role of surface Nafion adsorption in Ptcatalyzed oxygen reduction reaction by in situ electrical transport spectroscopy  

作　　者：Yamei Sun Jingyi Tian Zhangyan Mu Bailin Tian Qiulan Zhou Cheng Liu Shengtang Liu Qiang Wu Mengning Ding 

机构地区：[1]Key Laboratory of Mesoscopic Chemistry of MOE,State Key Laboratory of Analytical Chemistry for Life Sciences,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing210023,China

出　　处：《Science China Chemistry》2022年第11期2290-2298,共9页中国科学（化学英文版）

基　　金：supported by the Natural Science Foundation of China(22172075 and 92156024);the Fundamental Research Funds for the Central Universities in China(14380273);Natural Science Foundation of Jiangsu Province(BK20220069);Beijing National Laboratory for Molecular Sciences(BNLMS202107);the Thousand Talents Plan of Jiangxi Province(jxsq2019102002)。

摘　　要：Solid-state ionic conductor is a vital part in all electrochemical energy conversion devices. As a widely-applied protonconducting polymer and stabilizer for electrode preparation, Nafion has key applications in electrochemical devices operated under acidic conditions. Specific adsorption of Nafion on the catalyst surface is considered to result in partial loss of intrinsic activity in reactions such as oxygen reduction reaction(ORR), due to its comprehensive occupation of active sites. Many in situ characterization methods such as voltammetric fingerprinting and spectroscopic approaches have been used to explore the dynamic adsorption of Nafion on the electrode surface. However, most of current efforts have been focused on the behaviors of Nafion itself, with little attention paid to its effects on the adsorption of surface intermediates. Here, we employed the in situ electrical transport spectroscopy(ETS) to investigate Nafion adsorption on Pt catalysts and its effects on the ORR intermediates.Our findings suggest that specific adsorption of Nafion results in the increased coverage of oxygen intermediates with weaker adsorption strength, which in turn plays a critical role in the reaction selectivity. The successful application of ETS on the dynamic characterization of reaction intermediates provides a novel perspective for catalyst design in ORR-related applications in future sustainable chemistry.

关 键 词：electrical transport spectroscopy Nafion adsorption oxygen reduction reaction PLATINUM hydrogen peroxide 

分 类 号：O643.36[理学—物理化学]