Paper HC+SS-TuA11
Electronic Structure and Catalytic Properties of Au/h-BN Composite System

Tuesday, October 31, 2017, 5:40 pm, Room 25

Rational designing of functionalized materials owning superior properties than those of their constituents is of great importance for potential applications. Herein, we study the electronic structure and catalytic properties of subnanometer sized gold nanoparticle (Au₁₃) supported on hexagonal boron nitride (h-BN) with single boron vacancy, employing density functional theory including van der Waals (vdW) interaction. The electronic interaction between Au₁₃ and h-BN is strongly facilitated by the formation of covalent bonds between an Au atom and three N atoms (the first-nearest neighbors of B vacancy), giving rise to the frontier states (near Fermi energy), which spatially distribute around the corner Au atoms as well as the Au atom that occupies the B vacancy site. We examine CO oxidation, as a prototype reaction, on Au₁₃/h-BN via the peroxo-type (OOCO) reaction path. Our results reveal that the highly active sites for CO activation are the corner Au atoms where the frontier states are localized. The strong affinity of CO to bind at those sites, with binding energy of 0.84 eV, can also be understood in terms of the negatively charged Au atoms. The reaction energy and the activation barriers for the reaction OOCO*’CO₂(g)+O*, are found to be -2.28 eV and 0.10 eV, respectively whereas they are -1.89 eV and 0.12 eV for the reaction CO*+O*’CO₂(g). These results suggest that Au/h-BN composite can catalyze the CO oxidation even at the low temperature.

Work is supported by DOE grant DE-FG02-07ER15842.