Pt Single Atoms Supported on Defect Ceria as an Active and Stable Dual-Site Catalyst for Alkaline Hydrogen Evolution
Dung Van Dao, Giovanni Di Liberto, Sunny Yadav, Periyayya Uthirakumar, Kai Chen, Gianfranco Pacchioni, In‐Hwan Lee
Abstract
This work evaluates the feasibility of alkaline hydrogen evolution reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria (Pt 1 /CeO x ) as an active and stable dual-site catalyst. The catalyst displayed a low overpotential and a small Tafel slope in an alkaline medium. Moreover, Pt 1 /CeO x presented a high mass activity and excellent durability, competing with those of the commercial Pt/C (20 wt %). In this picture, the defective CeO x is active for water adsorption and dissociation to create H* intermediates, providing the first site where the reaction occurs. The H* intermediate species then migrate to adsorb and react on the Pt 2+ isolated atoms, the site where H 2 is formed and released. DFT calculations were also performed to obtain mechanistic insight on the Pt 1 /CeO x catalyst for the HER. The results indicate a new possibility to improve the state-of-the-art alkaline HER catalysts via a combined effect of the O vacancies on the ceria support and Pt 2+ single atoms.