Substrate-dependent catalytic activity of single-atom Pt for CO oxidation

Abstract

In recent years, numerous single-atom catalysts (SACs) have emerged and showed superior catalytic performance. Although different substrates lead to diverse activity, the substrate-dependent catalytic mechanism is still unrevealed. In this work, by taking the CO oxidation reaction as a representative, we have investigated the substrate-dependent catalytic activity of single-atom Pt using different inorganic perovskites (ABO₃) as the substrates. It is found that the interaction between the single atom Pt and substrates plays a crucial role in determining the catalytic activity, and the stronger interaction of Pt with the substrates could stabilize the active centre towards a significantly lower energy barrier for CO oxidation. Furthermore, a simple descriptor of the angle of adsorbed CO is proposed to estimate the reaction barrier. The larger tilt angle of the adsorbed CO represents the relatively stronger adsorption strength of CO with Pt, resulting in a higher energy barrier for CO oxidation. Finally, Pt–SrNiO₃ and Pt–SrAgO₃ are screened out as promising SACs for the CO oxidation reaction with low barriers of 0.64 eV and 0.71 eV, respectively. Therefore, the catalytic performance of single-atom Pt catalysts could be efficiently regulated by the substrates to achieve high stability and activity.