Сatalysts for Electrooxidation of Biomass Processing Products

In recent years, active research has been carried out in the field of catalysts for the electrooxidation of water-soluble products of biomass processing on the anodes of electrolysers, coupled with the process of producing hydrogen at the cathodes of these devices. Biomass processing products that are promising for electrooxidation are glycerol, glucose, furfural and 5-hydroxymethylfurfural. The review examines studies of catalysts for the electrooxidation of glycerol, glucose, furfural, and 5-hydroxymethylfurfural based on metals of various groups. Electrooxidation of these organic compounds on catalysts based on noble metals (platinum group metals and gold) and their alloys begins in the potential range from 0.3 to 0.7 V [reversible hydrogen electrode (RHE)], reaching a maximum at 1 V (RHE). The main disadvantage of catalysts based on noble metals is their high cost. Nickel and сobalt are considered promising among the non-noble metals studied as components of catalysts for these reactions. But in the presence of catalysts based on these metals, the electrooxidation reactions of the noted organic compounds begin at potentials above 1 V (RHE). Glyceraldehyde, dihydroxyacetone, glyceric, tartronic, glycolic, oxalic, glyoxalic and mesoxalic acids can be obtained from the electrooxidation of glycerol. Valuable products of the electrooxidation of glucose, furfural, and 5-hydroxymethylfurfural are gluconic, 2-furancarboxylic, and 2,5-furandicarboxylic acids, respectively.