Electrochemical Hydrogen Generation by Oxygen Evolution Reaction‐Alternative Anodic Oxidation Reactions

• Published in: Advanced energy and sustainability research Vol. 3; no. 7
• Main Authors: Liu, Xi, Han, Yue, Guo, Yao, Zhao, Xueting, Pan, Duo, Li, Kangkang, Wen, Zhenhai
• Format: Journal Article
• Language: English
• Published: Argonne John Wiley & Sons, Inc 01.07.2022; Wiley-VCH
• Subjects: Alcohol; alternative anode reactions; Alternative energy sources; Alternative fuels; Anodizing; Biomass; Carbon; Chemical reactions; Electricity; Electrocatalysts; Electrochemistry; Electrolysis; Energy consumption; Energy efficiency; Evolution; Fossil fuels; High temperature; hybrid electrolysis; Hydrogen; Hydrogen evolution reactions; Hydrogen production; NMR; Nuclear magnetic resonance; Oxidation; Oxygen evolution reactions; small-molecule electro-oxidation; Splitting; Sustainable energy; Water; Water splitting
• ISSN: 2699-9412; 2699-9412
• DOI: 10.1002/aesr.202200005

Hydrogen (H2) as an environmentally friendly and sustainable energy carrier has been regarded as one of the most promising alternatives to carbon‐based fossil fuels. Electrochemical water splitting powered by renewable electricity provides a promising strategy for H2 production, but its energy efficiency is strongly limited by the kinetically sluggish anodic oxygen evolution reaction (OER), which consumes ≈90% electricity in the water‐splitting process. A new strategy is urgently needed to reduce its energy consumption. Small‐molecule electro‐oxidation reactions that replace OER have attracted increasing attention due to the advantages of low theoretical thermodynamic potential and the benefit of producing value‐added chemicals compared with OER. Hybrid electrolysis systems, by coupling cathodic hydrogen evolution reaction (HER) with anodic small‐molecule oxidation reactions, have been proposed, which can produce high‐purity H2 and value‐added products. This review aims to systematically summarize the recent research on OER‐alternative reactions at the anode for energy‐efficient water splitting. The state‐of‐the art electrocatalysts for OER‐alternative reactions are first presented. The electrolysis performance in hybrid electrolysis regarding the conversion rate, selectivity, yield, and corresponding Faraday efficiency of anodic value‐added products is then evaluated. Finally, the challenges and perspectives are discussed and it is suggested to develop energy‐efficient and economically viable hybrid electrolysis systems. This review briefly summarizes the progress in emerging electrolysis H2 generation systems with alternative electro‐oxidation reactions to oxygen evolution reaction. This review describes a panorama of various types of alternative anodic oxidation reactions providing important guidance and can inspire future energy‐efficient and economically feasible hybrid electrolysis systems.