Insights into the Interfacial Lewis Acid–Base Pairs in CeO<sub>2</sub>‐Loaded CoS<sub>2</sub> Electrocatalysts for Alkaline Hydrogen Evolution
Jiayuan Li, Zhaoming Xia, Qingyu Xue, Mingkai Zhang, Sai Zhang, Hai Xiao, Yuanyuan Ma, Yongquan Qu
Abstract
Abstract Despite the known efficacy of CeO 2 as a promoter in alkaline hydrogen evolution reaction (HER), the underlying mechanism of this effect remains unclear. CoS 2 , a pyrite‐type alkaline HER electrocatalyst, suffers from sluggish HER kinetics and severe catalyst leaching due to its weak water dissociation kinetics and oxygen‐related corrosion. Herein, it is demonstrated that the interfacial Lewis acid–base Ce∙∙∙S pairs in CeO 2 ‐loaded CoS 2 effectively improve the catalytic activity and durability. In CeO 2 ‐loaded CoS 2 nanowire array electrodes, these interfacial Lewis acid–base Ce∙∙∙S pairs with unique electronic and structural configurations efficiently activate water adsorptive dissociation and kinetically accelerate hydrogen evolution, delivering a low overpotential of 36 mV at 10 mA cm −2 in alkaline media. Such Ce∙∙∙S pairs also weaken O 2 adsorption on CoS 2 , leading to undecayed activity over 1000 h. These findings are expected to provide guidance for the design of CeO 2 ‐based electrocatalysts as well as other hybrid electrocatalysts for water splitting.