Electronic Structure Modulation of Nickel Sites by Cationic Heterostructures to Optimize Ethanol Electrooxidation Activity in Alkaline Solution
Xiulan Li, Mingchuang Chen, Yanting Ye, Chengjie Chen, Zilong Li, Yifan Zhou, Jian Chen, Fangyan Xie, Yanshuo Jin, Nan Wang, Hui Meng
Abstract
It is a good idea for efficient production of hydrogen to use ethanol oxidation reaction (EOR) in place of oxygen evolution reaction (OER) in water electrolysis process. Ni-based non-precious electrocatalysts are widely used in the conversion of ethanol to acetic acid. Here, different selenide heterostructures (NiCoSe, NiFeSe, and NiCuSe) are prepared in which Ni sites are regulated by transition metal. The valence state of Ni is NiCuSe < NiCoSe < NiFeSe in the three heterojunctions. NiCoSe shows the optimized charge distribution of Ni sites and outstanding catalytic activity. The effective modulations lead to optimized d-band center and facilitates both adsorption and desorption of reaction intermediates, which improves the kinetics of EOR. The results of this work prove that with appropriate designed catalyst it is possible to replace kinetically slow OER with faster EOR in water electrolysis to produce hydrogen.