Recent advances in glycerol valorization through electrocatalytic methods

The recent tremendous growth of biodiesel production from vegetable oils or waste fats has led to increased glycerol accumulation as a by-product of this process. This sparked attention towards glycerol use and valorization of this largely available and cheap compound. Among several methods for glycerol valorization, electrochemical glycerol oxidation reaction (EGOR) is an attractive alternative anodic reaction to oxygen evolution reaction for a variety of electrolytic synthesis, due to the low thermodynamic potential. Consequently, the EGOR at the anode can be coupled with a cathodic hydrogen evolution reaction to achieve efficient energy conversion in an aqueous electrolytic cell. This review provides a comprehensive summary and critical analysis of glycerol electrochemical oxidation research during the last 5 years. This review focuses on the recent development and prospects of electrochemical pathways (indirect or direct routes) for application in the EGOR. In particular, the recent development and prospects of using noble and non-noble group metal catalysts for glycerol electro-oxidation are discussed. Eventually, reaction product selectivity analysis and conversion efficiency are also highlighted.