Developments and Challenges of Catalytic Materials for Green Hydrogen Production

Water splitting coupled to renewable power systems is an attractive way to generate green hydrogen and achieve zero carbon emissions, and represents a strategic technology to meet the high demand of carbon-neutral development. Catalysts essentially determine the efficiency and cost of water splitting technologies, and are a class of key materials for green hydrogen production. In this review, we summarize the catalyst developments for the mainstream green hydrogen production technologies, including water electrolysis, water photolysis, and photoelectrocatalytic water splitting. We first present basic catalytic mechanisms of these water splitting pathways, as well as emphasize their current research status and challenges for practical application. We subsequently introduce the recent progress in representative catalysts and design strategies toward these photo(electro)catalytic technologies, paying particular attention to water electrolysis, including alkaline water electrolyzer (AWE), proton exchange membrane water electrolyzer (PEMWE), anion-exchange membrane water electrolyzer (AEMWE) and solid oxide electrolysis cell (SOEC). Finally, we propose future prospects to develop more desirable catalysts for green hydrogen production at a large scale.