▎ 摘 要
The oxidation mechanisms of CO to CO2 on graphene-supported Pt and Pt-Al alloy clusters are elucidated by reactive dynamical simulations. The general mechanism evidenced is a Langmuir-Hinshelwood (LH) pathway in which O-2 is adsorbed on the cluster prior to the CO oxidation. The adsorbed O-2 dissociates into two atomic oxygen atoms thus promoting the CO oxidation. Auxiliary simulations on alloy clusters in which other metals (Al, Co, Cr, Cu, Fe, Ni) replace a Pt atom have pointed to the aluminum doped cluster as a special case. In the nanoalloy, the reaction mechanism for CO oxidation is still a LH pathway with an activation barrier sufficiently low to be overcome at room temperature, thus preserving the catalyst efficiency. This provides a generalizable strategy for the design of efficient, yet sustainable, Pt-based catalysts at reduced cost.