Hybrid water electrolysis with integrated and cascading reactions using two-dimensional electrocatalysts

Abstract

Electrocatalytic water splitting is promising for green hydrogen production. However, the high energy barrier and sluggish kinetics of the anodic oxygen evolution reaction (OER) lead to high energy consumption, burdening the large-scale industrial application. Hybrid water electrolysis using two-dimensional (2D) electrocatalysts is considered as a promising way to reduce the cost of electrocatalytic green hydrogen production. It reduces the electricity cost by earth-abundant electrode materials, alternative energy-saving reactions, and novel electrolyzers. In this review, we systematically analyze the promising hybrid water electrocatalysis by 2D electrocatalysts. The advantages and status quo, as well as important future directions and feasibilities of this emerging field, are carefully discussed. We reveal that developing well-matched alternative reactions and stable reactors/devices are two critical factors for efficient hybrid water electrolysis. To improve the practical and economic feasibility of hybrid water electrocatalysis, it is promising to integrate tandem reactions with hybrid water electrocatalysis and advanced electrolyzers to achieve higher efficiency and selectivity. We conclude that developing stable 2D electrocatalysts, finding matched reactions, and efficient devices are the core for advancing hybrid water electrocatalysis.