Recent advances in hydrogen production coupled with alternative oxidation reactions

The production of hydrogen through water electrolysis has garnered significant interest and extensive research as a sustainable and environmentally friendly method. However, the process of water splitting is thermodynamically unfavorable, and the slow oxygen evolution reaction (OER) with four-electron transfer significantly hinders overall efficiency. In order to overcome this limitation, researchers have conducted comprehensive analyses of the OER mechanism and have made remarkable progress on the development of superior catalysts. However, the reaction rate of OER remains limited due to the significant theoretical overpotential. Consequently, an alternative approach involving the substitution of OER with other low-energy anodic reactions has emerged as a promising avenue for reducing the potential required for hydrogen production and overall energy consumption. This review aims to provide a comprehensive summary of the advancements in hybrid water electrolysis as well as analyze the characteristics, advantages, and disadvantages of prevalent small molecule oxidation methods, with a particular focus on catalyst design and modification mechanisms. Additionally, strategies for enhancing high current performance are discussed. This review concludes by addressing the challenges and future prospects of hybrid water electrolysis, offering guidance for the systematic development of catalysts with enhanced efficiency.