Catalytic activity of Pd ensembles incorporated into Au nanocluster for CO oxidation: A first-principles study

We investigated the catalytic activity of Pd atoms incorporated into Au(111) facet through first-principles calculations, and found that the Pd monomer, dimer, and trimer are highly reactive for the reaction of CO+O2→CO2+Ovia association mechanism, in which an intermediate state (OOCO) is formed. Significantly, a low energy barrier (0.19-0.32 eV) was found for the formation of OOCO. The atomic oxygen left by CO+O2→CO2+O reaction can be removed by another CO on Pd-decorated Au cluster via Langmuir-Hinshelwood or Eley-Rideal mechanism. Our studies indicate Pd ensembles incorporated into Au(111) facet markedly improve the catalytic activity of gold nanocluster. -- Highlights: → Our results reveal the mechanism of CO oxidation on PdAu nanocatalysts. → Pd monomer, dimer, or trimer can significantly catalytic activity of Au facet. → 'Ensemble effects' is theoretically studied on PdAu cluster for CO oxidation firstly. → Our calculations are important for designing and synthesizing Au-base nanocatalysts.