Fine-tuned local coordination environment of Pt single atoms on ceria controls catalytic reactivity

Abstract

Constructing single atom catalysts with fine-tuned coordination environments can be a promising strategy to achieve satisfactory catalytic performance. Herein, via a simple calcination temperature-control strategy, CeO₂ supported Pt single atom catalysts with precisely controlled coordination environments are successfully fabricated. The joint experimental and theoretical analysis reveals that the Pt single atoms on Pt₁/CeO₂ prepared at 550 °C (Pt/CeO₂-550) are mainly located at the edge sites of CeO₂ with a Pt–O coordination number of ca. 5, while those prepared at 800 °C (Pt/CeO₂-800) are predominantly located at distorted Ce substitution sites on CeO₂ terrace with a Pt–O coordination number of ca. 4. Pt/CeO₂-550 and Pt/CeO₂-800 with different Pt₁-CeO₂ coordination environments exhibit a reversal of activity trend in CO oxidation and NH₃ oxidation due to their different privileges in reactants activation and H₂O desorption, suggesting that the catalytic performance of Pt single atom catalysts in different target reactions can be maximized by optimizing their local coordination structures.

CeO₂-supported Pt single atoms with different coordination environments exhibit distinct behaviors in reactant adsorption/activation and product desorption, thus showing different catalytic performance for various catalytic oxidation reactions.