Current status of developed electrocatalysts for water splitting technologies: from experimental to industrial perspective.

The conversion of electricity into hydrogen (H) gas through electrochemical water splitting using efficient electrocatalysts has been one of the most important future technologies to create vast amounts of clean and renewable energy. Low-temperature electrolyzer systems, such as proton exchange membrane water electrolyzers, alkaline water electrolyzers, and anion exchange membrane water electrolyzers are at the forefront of current technologies. Their performance, however, generally depends on electricity costs and system efficiency, which can be significantly improved by developing high-performance electrocatalysts to enhance the kinetics of both the cathodic hydrogen evolution reaction and the anodic oxygen evolution reaction. Despite numerous active research efforts in catalyst development, the performance of water electrolysis remains insufficient for commercialization. Ongoing research into innovative electrocatalysts and an understanding of the catalytic mechanisms are critical to enhancing their activity and stability for electrolyzers. This is still a focus at academic institutes/universities and industrial R&D centers. Herein, we provide an overview of the current state and future directions of electrocatalysts and water electrolyzers for electrochemical H production. Additionally, we describe in detail the technological framework of electrocatalysts and water electrolyzers for H production as utilized by relevant global companies.