Breaking the salt barrier: catalysts for efficient seawater electrolysis

Project summary

A viable path toward attaining energy sustainability is the production of green hydrogen using renewable energy sources. Nonetheless, conventional water electrolysis technologies predominantly rely on freshwater, exacerbating strain on already limited resources. Seawater, as a vast and natural electrolyte source, provides an alternative but poses significant challenges, including complex ionic chemistry, insoluble by-products formation, corrosionrelated issues, and chlorine evolution/oxidation reactions. Crucially, improving energy efficiency is imperative to mitigate the overall cost of hydrogen production from seawater.

Addressing these challenges involves developing high-performance electrocatalysts tailored for seawater electrolysis to achieve industrial-level oxygen evolution reaction (OER) current density below the potential at which competitive chlorine evolution reactions occur. Among potential candidates, transition-metal nitrides (TMNs) stand out as promising electrocatalysts due to their electron configurations, high electrical conductivities, corrosion resistance, and robust mechanical properties. Moreover, molybdenum (Mo) surfaces serve as electron pumps or reservoirs, modulating the electronic states of TMNs and enhancing catalytic activity through charge transfer. Additionally, ultra-thin graphitic carbon coatings can provide excellent conductivity and protective layers.

This research project aims to resolve the competition between the OER and other side reactions by pioneering the development of innovative high-performance Mo/TMNs electrocatalyst, with ultra-thin graphitic carbon coating.