First-principle calculations on CO oxidation catalyzed by subnanometer AlAun clusters

•Mixing metals Al and Au can have beneficial effects on the catalytic activity.•The alloyed AlAu2 cluster is proposed as the effective nanocatalysts.•AlAun transform to complexes which catalyze CO oxidation by LH and ER paths.•Strong adsorption of reactants on a catalyst is an effective indicator to assess catalytic activities.

We have elucidated the mechanism of CO oxidation catalyzed by AlAun (n = 1–3) clusters through first-principle density-functional theory (DFT) calculations. It is found that these subnanometer species transform into reaction complexes which catalyze CO oxidation through a variety of different mechanisms, occurring via both Langmuir–Hinshelwood and Eley–Rideal paths. It is shown that mixing two different metals (Al and Au) can have beneficial effects on the catalytic activity and the alloyed AlAu2 cluster is proposed as the best effective nanocatalyst.

Graphical abstractPotential energy surfaces for CO oxidation promoted by AlAu2.Figure optionsDownload full-size imageDownload as PowerPoint slide