Directional Electrosynthesis of Adipic Acid and Cyclohexanone by Controlling the Active Sites on NiOOH

Abstract

Dicarboxylic acids and cyclic ketones, such as adipic acid (AA) and cyclohexanone (CHN), are essential compounds for the chemical industry. Although their production by electrosynthesis using electricity is considered one of the most promising strategies, the application of such processes has been hampered by a lack of efficient catalysts as well as a lack of understanding of the mechanism. Herein, a series of monolithic msig/ea-NiOOH-Ni(OH) 2 /NF were prepared by means of self-dissolution of metal matrix components, interface growth, and electrochemical activation (denoted as msig/ea). The as-synthesized catalysts have three-dimensional cuboid-like structures formed by interconnecting nanosheets composed of NiOOH. By theoretically guided regulation of the amounts of Ni 3+ and oxygen vacancies (O V ), a 96.5% yield of CHN from cyclohexanol (CHA) dehydrogenation and a 93.6% yield of AA from CHN oxidation were achieved. A combined experimental and theoretical study demonstrates that CHA dehydrogenation and CHN oxidation were promoted by the formation of Ni 3+ and the peroxide species (*OOH) on O V . This work provides a promising approach for directional electrosynthesis of highpurity chemicals with in-depth mechanistic insights.

Effects of Manganese Doping into Nickel Hydroxides for the Electrochemical Conversion of KA Oil

“…The electrochemical activity of the as-prepared samples for the oxidation of KA oil was first evaluated in a single undivided cell using an electrolyte of 1 M KOH + 0.1 M KA oil. As indicated in Figure S6, the CV curves of Ni­(OH) 2 /CP recorded in 1 M KOH reveal an oxidation peak at about 1.48 V, corresponding to the oxidation process of Ni­(OH) 2 to NiOOH, , followed by the oxidation wave of the oxygen evolution reaction (OER). A reduction peak related to Ni 3+ /Ni 2+ appears during the negative sweep of the potential.…”