A stable, reactive, and cost-effective ruthenium catalyst for sustainable hydrogen production through proton exchange membrane water electrolysis
In a recent study published in Volume 88 of the Journal of Energy Chemistry in January 2024, a group of researchers, led by Professor Haeseong Jang from the Department of Advanced Materials Engineering at Chung-Ang University, has developed a promising OER catalyst, the university announced.
Denoted as SA Zn-RuO2, the catalyst comprises of RuO2 stabilized by single atoms of zinc. Elaborating about their study, Prof. Jang says, “We were motivated by the need to find efficient and cost-effective alternative electrocatalysts for OER in PEM water electrolysis. Based on our study, we propose a dual-engineering strategy, involving single atom Zn doping and the introduction of oxygen vacancies, to balance high catalytic activity with stability during acidic OER.”
The researchers synthesized SA Zn-RuO2 by heating an organic framework with ruthenium (Ru) and zinc atoms, forming a structure with oxygen vacancies (missing oxygen atoms that positively alter the properties) and Zn-O-Ru linkages. These linkages stabilize the catalyst in two ways—one, by strengthening the Ru-O bonds, and second, by providing electrons from zinc atoms to protect ruthenium from overoxidation during the OER process. Furthermore, the improved electronic environment around the ruthenium atoms lowers the energies needed for molecules to stick to the surface, thus lowering the energy barrier for the reaction.
The resulting catalyst was more stable, with no apparent fall in reactivity, and significantly outperformed commercial RuO2. Moreover, it required less extra energy (low overpotential of 213 mV compared to 270 mV for commercial RuO2) and remained functional for a longer period (43 hours compared to 7.4 hours for commercial RuO2).
Due to its improved stability and features, the newly proposed SA Zn-RuO2 catalyst has the potential to influence the development of cost-effective, active, and acid-resistant electrocatalysts for OER. This, in turn, could help in reducing costs and enhancing the production of green hydrogen, aiding in a shift toward cleaner energy sources and advancements in sustainable technologies.
In summary, the highly reactive and catalytically stable RuO2 catalyst for the acidic OER has increased durability and favorable characteristics, and holds immense potential for guiding the design of robust and active non-iridium-based OER electrocatalysts for practical applications!
Reference
Journal: Journal of Energy Chemistry
DOI: https://doi.org/10.1016/j.jechem.2023.09.010
Chung-Ang University: https://neweng.cau.ac.kr/index.do