Recent Advances in Electrocatalysts toward Alcohol-Assisted, Energy-Saving Hydrogen Production

As a pure and sustainable source of power, hydrogen (H2) is the desired chemical candidate for the future energy mix. Water electrolysis has been regarded as an effective method for producing clean and ultrapure hydrogen gas. However, its large-scale applications are hampered by its slow kinetics, particularly due to its slow anodic half-reaction i.e., the oxygen evolution reaction (OER). Another strategy based on chemical-assisted electrocatalytic energy-saving hydrogen production has recently been developed with great potential to address barriers associated with OER. In this case, OER is replaced by organic oxidation reactions that are thermodynamically more favorable, which substantially reduces the voltage required for H2 evolution and also facilitates the co-production of organic value-added products. Oxidation of biomass derivatives, such as alcohols, is the most suitable strategy for producing value-added chemicals with energy-saving hydrogen production. This Review focuses on the characteristics of making electrolytic hydrogen production more cost-efficient by using different alcohols. We have reviewed the fundamentals and key parameters for alcohol-assisted electrochemical hydrogen production and discussed several anodic alcohol oxidation reactions with value-added products. The choice of electrocatalysts, strategies to increase the reaction selectivity, and the possible cell architectures are elaborated in detail.