Identification of the Catalytic Site at the Interface Perimeter of Au Clusters on Rutile TiO₂(110)

Abstract

We present a density functional theory study of the CO oxidation reaction at a Au 24 cluster supported on a rutile TiO 2 (110) slab. The global minimum structure of the Au 24 cluster is found using a genetic algorithm search. Catalytic sites are found at the perimeter of the Au−TiO 2 interface but with strong dependence on the surface direction. It is shown how the CO oxidation reaction only happens along the [11̅ 0] direction of the support and not along the [001] direction. This effect is attributed to a too weak CO binding energy along the [001] direction caused by the charge state and Au−Au coordination of the Au atoms along this direction.

An oxidized magnetic Au single atom on doped TiO2(110) becomes a high performance CO oxidation catalyst due to the charge effect

“…[4][5][6][7][8][9][10] Accordingly, a number of mechanisms have been proposed to elucidate the enhanced activities of Au NPs, including an odd number of electrons, 11 the quantum size effect, 11,12 metal-nonmetal transitions in a given cluster size regime, 13 and the presence of poorly coordinated edge or corner atoms. [14][15][16] Moreover, it is also widely recognized that the interactions between the Au and the support, including the strain effect, 17 the charge state [18][19][20][21] of the Au atom, and particularly the charge transfer between the Au NPs and the substrates 22 have been regarded to be crucial in determining the performance of the Au NPs.…”

Reaction Network of Methanol Synthesis over Cu/ZnO Nanocatalysts

“…[4][5][6]. Moreover, using deposited cluster models consisting on the order of ten metal atoms is commonplace in state-of-the-art computational catalysis studies [120][121][122][123][124][125] in which chemical interactions and reactions are studied based on non-semiempirical electronic structure methods (it is noted that these studies are mostly carried out in the static optimization limit, whereas we carry out full ab initio simulations at finite temperature in the present investigation). Most importantly, studying heterogeneous catalysis in the limit of small, size-selected clusters is by now a well-established and useful contribution to understanding the related industrial processes [126][127][128][129][130][131][132] .…”

Reverse Water–Gas Shift on Interfacial Sites Formed by Deposition of Oxidized Molybdenum Moieties onto Gold Nanoparticles

“…11,12 To date, the major factors contributing to catalytic activity are thought to be under-coordinated Au atoms, 5,13 the geometry of the Au clusters, 14,15 the oxidation state of Au atoms, [16][17][18] and the interface between Au and the metal oxide support. 3,[19][20][21] In spite of considerable research in this area, there is still uncertainty in the identification and quantification of the catalytically active sites for gold catalysts.…”

“…Activation of reactants at the Au-metal oxide interface is widely proposed to be a key step for reactions such as H 2 dissociation, 4,22 CO oxidation 19,[23][24][25][26][27] , WGS, and reverse water-gas shift (RWGS). [28][29][30][31][32][33][34][35][36][37] Rodriguez et al studied WGS over Au/TiO 2 (110), and on the basis of experiments and theoretical calculations they concluded that the metalsupport interface is critical for the activation of water and the formation of a carboxyl intermediate which further decomposes into CO 2 and H 2 .…”