Deciphering the hydrophilic behavior and vibrational characteristics of the θ-Al2O3(010) surface

Abstract

One of the long-term goals of catalysis is to clarify and understand structure–function relationships. In this work, hydrophilicity of the θ-Al₂O₃ surface is simulated. The results show sustained H₂O/OH adsorption at unsaturated Al sites on the thermodynamically stable θ-Al₂O₃(010) surface. Furthermore, the multilayer water-covered (010) surface, which possesses highly stable –OH groups, was simulated using ab initio molecular dynamics simulations for modeling surface hydroxylation, and also shows a dynamic proton transfer process. Finally, the infrared vibrational characteristics of the hydroxylated θ-Al₂O₃ surface were analyzed by using atomic velocity autocorrelation functions and vibrational density of states to determine the structure of the (010) surface, which provides valuable guidance for understanding the hydroxylated θ-Al₂O₃ catalysts.