Abstract

Using Density Functional Theory (DFT), the interaction of crucial molecules involved in the selective partial oxidation of methanol to methyl formate (MF), with monometallic Au, Pd and bimetallic Au/​Pd, Pd/​Au core@shell catalysts is systematically investigated. The core@shell structures modeled in this study consist of Au(111), Pd(111) cores covered by monolayer of Pd, Au, respectively. Our results indicate that the adsorption strength of the molecules examined as a function of catalytic surface decreases in the order of Au/Pd(111) > Pd(111) > Au(111) > Pd/Au(111) and correlate well with the d‑band center model. The preadsorbtion of oxygen is found to have a positive impact on the selective partial oxidation reaction due to the stabilization of CH3OH and HCHO on the catalyst surface and the simultaneous intensification of MF desorption. Based on a dynamical matrix approach combined with statistical thermodynamic we propose a simple route for evaluating the Gibbs free energy of adsorption as a function of temperature. This method allows us to anticipate the relative temperature stability of molecules involved in the selective partial oxidation of methanol to MF in terms of catalytic surface.