Electronic Structure Modulation of Nickel Sites by Cationic Heterostructures to Optimize Ethanol Electrooxidation Activity in Alkaline Solution

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.

Automated summary

In order to produce hydrogen more efficiently, it is proposed to use ethanol oxidation reaction (EOR) instead of oxygen evolution reaction (OER) in water electrolysis. Ni-based non-precious electrocatalysts are commonly used for the conversion of ethanol to acetic acid. Different selenide heterostructures (NiCoSe, NiFeSe, and NiCuSe) are prepared in this study, with the regulation of Ni sites by transition metals. Among the three heterojunctions, NiCoSe exhibits optimized charge distribution of Ni sites and outstanding catalytic activity. The effective modulations improve the kinetics of EOR by optimizing the d-band center and facilitating the adsorption and desorption of reaction intermediates.