Stability of Pt1/CeO2 single-atom catalyst in oxygen-poor environments: first-principles insights

Abstract

Abstract Due to its exceptional oxygen storage/release capabilities, excellent catalytic activity, and selectivity, the single-atom Pt1/CeO2 catalyst has demonstrated significant research prospects and development promise in fuel cell applications. Investigating how the Pt1/CeO2 system behaves in oxygen-poor environments has become a focal point of current research. In the present work, the formation of oxygen vacancies as well as their impact on the stability of Pt adsorption in different Pt1/CeO2 systems under oxygen-poor conditions is systematically investigated. The research findings indicate that the ease of oxygen vacancy formation is primarily dictated by the structure of the Pt1/CeO2 system, with a higher propensity in low-stability systems (PtOB/CeO2, PfCeT/CeO2, PtOT/CeO2). Oxygen vacancies tend to form away from Pt positions (at the 2NN positions). Oxygen-poor and high-temperature environments promote the formation of oxygen vacancies in Pt1/CeO2 systems. Furthermore, in low-stability systems, oxygen vacancies, through adjustments to the system’s electronic structure, such as increasing the quantity of Ce3+ polarons and the transferred charge amount of Pt atoms, significantly enhance the adsorption strength of Pt atoms. This study aims to offer new insights and avenues for the design of fuel cell catalysts, promoting practical applications and development in fuel cells.