pH-Dependent binding energy-induced inflection-point behaviors for pH-universal hydrogen oxidation reaction  

作　　者：Lixin Su Yiming Jin Xinran Fan Zeyu Liu Wei Luo 

机构地区：[1]Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials,College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China

出　　处：《Science China Chemistry》2023年第11期3262-3268,共7页中国科学（化学英文版）

基　　金：supported by the National Key Research and Development Program of China(2021YFB4001200);the National Natural Science Foundation of China(22272121,21972107);the Natural Science Foundation of Hubei Province(2020CFA095)。

摘　　要：The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.

关 键 词：hydrogen oxidation reaction inflection-point behaviors pH-dependent binding energy palladium phosphides 

分 类 号：TM911.4[电气工程—电力电子与电力传动] O643.36[理学—物理化学]