Tuning the selectivity of Pd-based catalysts for CO oxidative esterification: Regulating Pd's electronic effect

CO oxidative esterification is crucial in converting inorganic CO into organic oxygenated compounds within C1 chemistry and technology. However, understanding the structure-activity relationship underlying this reaction remains limited, primarily due to the entanglement of the Pd's geometric and electronic structures, which complicates selectivity control in practical applications. In this work, we design four Pd-based catalysts using the Al(111) motif to investigate their catalytic performance in CO oxidative esterification through density functional theory (DFT) calculations. Firstly, the larger lattice parameter of Al weakens horizontal Pd–Pd interactions while enhancing the vertical stability of Pd. Secondly, the electronic structure of Pd is locally regulated via charge transfer between subsurface and surface Pd, driven by their differences in work function. Our results indicate that the relative activity between CC coupling for dimethyl oxalate (DMO) and CO coupling for dimethyl carbonate (DMC) is primarily influenced by Pd's electronic effects, as revealed by energy barrier decomposition analysis. Thus, focusing on the regulation of Pd's electronic effects may offer a new strategy for controlling the selective oxidation esterification of CO.