Local environmental engineering for highly stable single-atom Pt1/CeO2 catalysts: first-principles insights

Abstract

Single-atom Pt1/CeO2 catalysts may cope with the high cost and durability issues of fuel cell electrocatalysts. In the present study, the stability and underlying interaction mechanisms of the Pt1/CeO2 system are systematically investigated using first-principles calculations. The Pt adsorption energy on CeO2 surfaces can be divided into chemical interaction and surface deformation parts. The interaction energy, mainly associated with the local chemical environment, i.e. the number of Pt-O bonds, plays a major role in Pt1/CeO2 stability. When forming a Pt-4O configuration, the catalytic system has the highest stability and Pt is oxidized to Pt2+. An electronic metal-support interaction mechanism is proposed for understanding Pt1/CeO2 stability. In addition, our calculations show that the Pt1/CeO2(100) system is dynamically stable, and the external O environment can promote the further oxidation of Pt to Pt n+ (2 ≤ n < 4). The present study provides useful guidance for the experimental development of highly stable and efficient electrocatalysts for fuel cell applications.