Activity Origins and Design Principles of Nickel-Based Catalysts for Nucleophile Electrooxidation

Understanding how electrocatalysts function in a nucleophile oxidation reaction (NOR) on anode, replacing the oxygen evolution reaction (OER) of water splitting, is vital to the development of hydrogen generation and organic electrosynthesis. Here, we propose that for beta-Ni(OH)(2) and NiO, the NOR activity origins are beta-Ni(OH)O containing electrophilic lattice oxygen and NiO(OH)ads containing electrophilic adsorption oxygen, respectively. For beta-Ni(OH)(2), NOR is a two-step, one-electron reaction, including an electrogenerated catalyst dehydrogenation reaction and a spontaneous nucleophile dehydrogenation reaction. Therefore, the NOR activity of beta-Ni(OH)(2) can be markedly regulated by tuning the lattice oxygen ligand environment. For beta-Co0.1Ni0.9(OH)(2), the onset potential of NOR with different nucleophiles is similar to 1.29 V (1 M KOH), which breaks the bottleneck of similar to 1.35 V for most nickel-based catalysts. Overall, we identify the activity origins and propose the design principles of nickel-based catalysts for NOR. These provide theoretical guidance for the development of NOR and organic electrosynthesis in practical industrial applications.