The Impact of Electronic Structure Modification on Lewis Acidity-Basicity and Reducibility of Doped La2O3

Abstract

Abstract Catalyst reactivity hinges on descriptors such as surface reducibility and Lewis acidity/basicity. This study systematically explores how doping the La2O3(001) surface with s-block, d-block and f-block heteroatoms modulates these properties. Dopant-induced changes in surface reducibility are quantified using oxygen vacancy formation energies, while cation-site Lewis acidity is probed by NH3 adsorption energies, and the strength of local acid–base interactions at oxygen-containing sites is compared using CO2 adsorption energies. Spin-averaged band centers of the unoccupied La 5d states and occupied O 2p states were calculated for doped La2O3(001) surfaces and correlated with these reactivity descriptors. The results reveal several clear trends: (i) Dopants with stable oxidation states lower than that of La exhibit low oxygen vacancy formation energies, strong electron-accepting abilities, and elevated d- and p-band centers caused by the formation of electron-deficient sites, whereas high-valent dopants exhibit the opposite behavior. (ii) A clear linear relationship is observed between the La 5d- or O 2p-band centers on defective doped La2O3(001) surfaces and the oxygen vacancy formation energy. (iii) In contrast, correlations between the La 5d- or O 2p-band centers and molecular adsorption-based Lewis acid–base descriptors are weaker. We find that the unoccupied dopant dz2 -band center exhibits an improved correlation with NH3 adsorption energy compared with the full dopant d-band center, providing an orbital-specific descriptor for understanding Lewis acidity trends.