A Single Layer of MoS2 Activates Gold for Room Temperature CO Oxidation on an Inert Silica Substrate

We demonstrate the facile deposition of catalytically active stable Au nanoparticles on single-layer MoS2, on an inert oxide substrate (SiO2). Unlike a gold surface, adsorption of CO on these gold particles proceeds even at room temperature. Subsequent exposure to oxygen leads to CO2 formation and desorption along a reaction pathway described, in detail, by density functional theory. The barrier to CO oxidation, along this pathway, is less than 300 meV, corroborating the facile nature of the CO oxidation reactions in this system. X-ray photoelectron spectroscopy directly reveals that the carbon monoxide, adsorbed on Au nanoparticles on single-layer MoS2, can be repeatedly titrated off the substrate by exposure to oxygen. Comparison of computational results assuming a defect-laden and pristine MoS2 substrate suggest that the pristine single-layer material may be superior in supporting this reaction.