CO adsorption on planar and tetrahedral Pt nanoclusters supported on TiO2(110) stoichiometric and reduced surface

A. MALDONADO; C.I.N. MORGADE; S.B. RAMOS; G. F. CABEZA

Montevideo

Congreso; 42nd International Congress of Theoretical Chemists of Latin Expression; 2016

Universidad de la República

In this work we use a Density Functional Theory (DFT+U) modeling method to study the structure and energetic of Pt4 clusters deposited on rutile TiO2(110) stoichiometric and reduced surfaces [1]. For the Pt-titania system we examine the relative stability between the planar (P) versus 3D tetrahedral (T) structures, and characterize the cluster/substrate interaction. We determine their equilibrium geometries, adsorption energies, charge transfer effects and electronic density of states to characterize different aspects of the metal-oxide interaction. For both, the stoichiometric and reduced rutile, we find that the flat square configuration is preferred, as experiments indicate [2]. In particular, we are interested in the potential activity of these cluster-supported systems for the oxidation of CO adsorbed on Pt. To examine this behavior we evaluate the structure, electronic DOS properties and charge transfer effects for the adsorption of CO on both the flat and tetrahedral Pt4 isomers overthe stoichiometric and reduced rutile surfaces. The results point to the planar cluster on the stoichiometric surface as the most stable configuration for CO adsorption, while for the carbon monoxide conversion to carbon dioxide the tetrahedral cluster on the stoichiometric rutile surface would be the most favorable catalytic substrate.[1] S.Dudarev, G. Botton, S. Savrasov, C. Humphreys, and A. Sutton, Phys. Rev. B, 57 (1998) 1505-1509.[2] Y.Watanabe, X. Wu, H. Hirata, and N. Isomura, Cat. Sci. Technol., 1 (2011) 1490-1495.