Non-precious metal-based catalysts for water electrolysis to produce H2 under industrial conditions

Hydrogen is the most promising energy carrier to replace fossil fuels due to its sustainability, environmental friendliness, and high energy efficiency. Green electricity can be used to power electrocatalytic water splitting, which produces green hydrogen. The industrial production of green hydrogen is critical to achieving carbon-neutrality. Herein, we have systematically summarized industrial electrolyzers and related mechanisms for the OER and HER in both alkaline and acid media. Then, catalyst design strategies for achieving industrial current density are discussed, followed by the illustration of bubble growth and the principle of catalyst stability. Recent advances in long-term water electrolysis under both traditional laboratory and quasi-industrial conditions are also discussed. Besides, scale-up methods and low-cost catalysts are studied to accommodate industrial manufacturing. Finally, challenges and perspectives of industrial green hydrogen production are highlighted. This review would provide useful insights into the mechanism, design, fabrication, improvement, and application of electrocatalysts for industrial hydrogen production.