Benchmark and Roadmap for Low Temperature Water Electrolysis for Green H2 Production and Applications

Water electrolysis has attracted world-wide attention due to its ability to produce green hydrogen when coupled with renewable electricity. Green hydrogen is a viable solution to decarbonizing a variety of industries including fertilizer, metal production, petrochemical, and synthetic fuels. There are three major low temperature water electrolysis technologies, alkaline water electrolyzer (AWE), proton exchange membrane water electrolyzer (PEMWE), and anion exchange membrane water electrolyzer (AEMWE). This work will first provide the status of these three technologies in terms of operating conditions, lifetime, and capital cost. Subsequently, the challenges and constraints for these technologies will be discussed in the scenarios of large-scale manufacturing and integration with intermittent renewables. More efforts will be made to illustrate the trajectory of the next-gen water electrolysis technologies, which feature at ultralow PGM or PGM-free catalysts, thin membranes with reduced hydrogen crossover, high-current high-power operation, long lifetime, and remarkable cost reduction. The work will also address the challenges of automated MEA fabrication and stack manufacturing at scale. Finally, a real example of renewable wind turbine integrated with water electrolyzer to produce green hydrogen and subsequently green ammonia will be demonstrated.