Clean and Affordable Hydrogen Fuel from Alkaline Water Splitting: Past, Recent Progress, and Future Prospects

• Published in: Advanced materials (Weinheim) Vol. 33; no. 31; pp. e2007100 - n/a
• Main Authors: Yu, Zi‐You, Duan, Yu, Feng, Xing‐Yu, Yu, Xingxing, Gao, Min‐Rui, Yu, Shu‐Hong
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.08.2021
• Subjects: alkaline water splitting; Catalysts; Chalcogenides; Chemical synthesis; Commercialization; Electrocatalysts; Electrolysis; Energy harvesting; Hydrogen; hydrogen energy; hydrogen evolution; Hydrogen evolution reactions; Hydrogen fuels; Hydrogen production; Hydrogen-based energy; Hydroxides; Industrial development; Materials science; oxygen evolution; Oxygen evolution reactions; Phosphides; Seawater; Transition metal alloys; Transition metal oxides; Water splitting
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202007100

Hydrogen economy has emerged as a very promising alternative to the current hydrocarbon economy, which involves the process of harvesting renewable energy to split water into hydrogen and oxygen and then further utilization of clean hydrogen fuel. The production of hydrogen by water electrolysis is an essential prerequisite of the hydrogen economy with zero carbon emission. Among various water electrolysis technologies, alkaline water splitting has been commercialized for more than 100 years, representing the most mature and economic technology. Here, the historic development of water electrolysis is overviewed, and several critical electrochemical parameters are discussed. After that, advanced nonprecious metal electrocatalysts that emerged recently for negotiating the alkaline oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are discussed, including transition metal oxides, (oxy)hydroxides, chalcogenides, phosphides, and nitrides for the OER, as well as transition metal alloys, chalcogenides, phosphides, and carbides for the HER. In this section, particular attention is paid to the catalyst synthesis, activity and stability challenges, performance improvement, and industry‐relevant developments. Some recent works about scaled‐up catalyst synthesis, novel electrode designs, and alkaline seawater electrolysis are also spotlighted. Finally, an outlook on future challenges and opportunities for alkaline water splitting is offered, and potential future directions are speculated. The hydrogen economy has emerged as a very promising alternative to the current hydrocarbon economy, which involves the process of harvesting renewable energy to split water into hydrogen and oxygen and then further utilization of hydrogen fuel. Alkaline water splitting represents the most mature and economic technology for clean hydrogen production, making high potential for successful implementation of hydrogen economy.