Benchmarking stable Electrocatalysts for green hydrogen production: A chemist perspective

Electro-induced water splitting module is a fascinating strategy for the conversion of electricity into scalable and clean H 2 as a future energy carrier and has significantly attracted the attention of the scientific community. Despite countless research on electrolyzers, cost-effective and durable electrode materials with high conversion efficiency remain a challenge and dream in this quest. This critical review is devoted to systemically presenting the upsurge of recently and rationally explored highly stable benchmark electrocatalysts (both noble and non-noble) to understand the design principles, performances, and compelling reasons/chemistry behind the enhanced catalytic potential over traditional electrocatalysts for half-cell oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Moreover, the highly stable electrode materials (at least ≥50 h) and their bi-functional conduct evaluated in prototype electrolyzer integrated with photovoltaic (PV) or batteries at the laboratory level are discussed, yet an untold and unsummarized story in electrochemical water splitting. Next, the current status of this technology, socio-economic challenges, possible solutions, key considerations and fundamental principles/concepts behind the water splitting conversion scheme are outlined from the point of practical application. Typical challenges remain regarding identifying, preparing, and scaling the potential electrocatalysts, but the foundations are now strong, and the outlook is visible for this exciting next-generation technology. • Critical Benchmark electrocatalysts (both noble and non-noble) for water splitting • Understanding the design principles, performances and mechanistic studies • Critical scrutiny of electrocatalysts for oxygen and hydrogen evolution reaction technology • Long term stability of electrocatalyst in Full cell investigation • PV integration of highly stable electrocatalysts