posted on 2024-01-20, 00:03authored byVandung Dao, Giovanni Di Liberto, Sunny Yadav, Periyayya Uthirakumar, Kai Chen, Gianfranco Pacchioni, In-Hwan Lee
This
work evaluates the feasibility of alkaline hydrogen evolution
reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria
(Pt1/CeOx) as an active and
stable dual-site catalyst. The catalyst displayed a low overpotential
and a small Tafel slope in an alkaline medium. Moreover, Pt1/CeOx presented a high mass activity
and excellent durability, competing with those of the commercial Pt/C
(20 wt %). In this picture, the defective CeOx 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
Pt2+ isolated atoms, the site where H2 is formed
and released. DFT calculations were also performed to obtain mechanistic
insight on the Pt1/CeOx 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 Pt2+ single atoms.