A review of anodic catalysts and their application in (non-)Kolbe electrocatalytic decarboxylation of carboxylic acids

Biomass, as the exclusive and abundant organic resources, is considered to be the promising renewable resource. Carboxylic acids are one of the many compounds that can be obtained from raw biomass. Decarboxylation of carboxylic acids into fuels and chemicals via electrochemical method at mild reaction condition has been studied for many years. The (non-)Kolbe reaction, one of the oldest organic electrochemical reactions, is the decarboxylation of carboxylic acids to produce alkanes, alcohols, esters, etc. And electrode materials influence the production of electrocatalytic decarboxylation products from carboxylic acids. Therefore, this work mainly reviews the recent advances in applications of anodic materials for (non-)Kolbe electrocatalytic decarboxylation of carboxylic acids. It discusses the reaction mechanism of (non-) Kolbe electrolytic reaction, and the electrocatalytic oxidation of carboxylic acid using different electrodes and electrolytic systems to synthesize fuels and chemicals. Also, various types of electrode catalysts, such as Pt-based catalysts, C-based catalysts, and other catalysts, are introduced in detail. Finally, the challenges and future trends of the (non-)Kolbe reaction of carboxylic acids are presented. This review found that platinum-based electrocatalysts proved to be the most promising catalysts at present. And in recent years, a variety of synthesis methods have been developed to synthesize small size and high-performance noble metal based amorphous catalysts. Another approach is to study catalysts without platinum electricity, such as Ru, Ir, Ti and carbon materials. The review is helpful in understanding and know the anodic materials and their application in (non-)Kolbe electrocatalytic decarboxylation of carboxylic acids for the readers.