CO adsorption on planar and tetrahedral Pt nanoclusters supported on Ti02(110) stoichiometric and reduced surface

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

Montevideo

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

Universidad de la República and Instituto Pasteur de Montevideo

TiO2 is a widely used material due to itselectronic and catalytic properties, which are of interest for technologicalapplications. In catalysis it is generally used as support for differentcatalyzers, such as for example Pt subnanoclusters given that they improve theefficiency of the material. In this work we use an ab initioDensity Functional Theory(DFT+U) modeling method to study the structure andenergetic of Pt4 clusters deposited on rutile TiO2(110)stoichiometric and reduced surfaces [1]. For the Pt-titania system we examinethe relative stability between the planar (P) versus 3D tetrahedral (T) Pt4structures, and characterize the cluster/substrate interaction. We determine their equilibrium geometries,adsorption energies, charge transfer effects and electronic density of statesto characterize different aspects of the metal-oxide interaction. For both, thestoichiometric and reduced rutile TiO2(110), we find that the flatsquare configuration is preferred, as experiments indicate [2]. In particular,we are interested in the potential activity of these cluster-supported systemsfor the oxidation of CO adsorbed on Pt. To examine this behavior we evaluatethe structure, electronic DOS properties and charge transfer effects for theadsorption of CO on both the flat and tetrahedral Pt4 isomers overthe stoichiometric and reduced TiO2 rutile surfaces. The resultspoint to the planar cluster on the stoichiometric surface as the most stableconfiguration for CO adsorption, while for the CO conversion to CO2the tetrahedral Pt4 cluster on the stoichiometric TiO2surface would be the most favorable catalytic substrate.