posted on 2023-08-11, 07:03authored byWei Tan, Shaohua Xie, Yandi Cai, Haowei Yu, Kailong Ye, Meiyu Wang, Weijian Diao, Lu Ma, Steven N. Ehrlich, Fei Gao, Lin Dong, Fudong Liu
Tuning the metal–support interaction and coordination
environment
of single-atom catalysts can help achieve satisfactory catalytic performance
for targeted reactions. Herein, via the facile control of calcination
temperatures for Pt catalysts on pre-stabilized Ce0.9Zr0.1O2 (CZO) support, Pt single atoms (Pt1) with different strengths of Pt–CeO2 interaction
and coordination environment were successfully constructed. With the
increase in calcination temperature from 350 to 750 °C, a stronger
Pt–CeO2 interaction and higher Pt-O-Ce coordination
number were achieved due to the reaction between PtOx and surface Ce3+ species as well as the migration
of Pt1 into the surface lattice of CZO. The Pt/CZO catalyst
calcined at 750 °C (Pt/CZO-750) exhibited a surprisingly higher
C3H8 oxidation activity than that calcined at
550 °C (Pt/CZO-550). Through systematic characterizations and
reaction mechanism study, it was revealed that the higher concentration
of surface Ce3+ species/oxygen vacancies and the stronger
Pt–CeO2 interaction on Pt/CZO-750 could better facilitate
the activation of oxygen to oxidize C3H8 into
reactive carbonate/carboxyl species and further promote the transformation
of these intermediates into gaseous CO2. The Pt/CZO-750
catalyst can be a potential candidate for the catalytic removal of
hydrocarbons from vehicle exhaust.