Theoretical insights into ω-alkynylfuran cycloisomerisation catalyzed by Au/CeO2(111): the role of the CeO2(111) support

Abstract

Understanding the role of CeO2(111) supports is meaningful for designing high-performance metal oxide-supported gold nanoparticle catalysts. Here, density functional theory calculations were employed to study ω-alkynylfuran cycloisomerisation on CeO2(111)-supported Au clusters. The various reactive sites, including the atop, interface and edge sites, and the role of oxygen vacancies on the defective CeO2(111) surface were taken into account. On the basis of the computed results and energetic analysis, it was found that the atop and interface sites show high catalytic activity toward ω-alkynylfuran cycloisomerisation, and the edge site of Au10/CeO2(111)-s (stoichiometric) exhibits similar catalytic activity. Meanwhile, the surface oxygen vacancies of CeO2(111) can cause some negative and positive effects on the adsorption energy and the catalytic activity. Furthermore, to shed light on the role of the CeO2(111) support, an analysis of ω-alkynylfuran cycloisomerisation catalyzed by Au3-4/CeO2(111) and free Au3-4 clusters was performed as well. Our results indicate that the presence of the CeO2(111) support can not only change the orbital levels of the gold clusters, but also cause charge recombination and decrease the positive charge on the Au (top) atom. These virtues can effectively lead to a decrease in the adsorption energy, facilitating electrophilic attack of the C atom on the furan ring.