Nanoporous TiO₂-supported bimetallic catalysts for methanol oxidation in acidic media

New dynamic aspects of the catalysis of methanol oxidation reaction have been studied. The submonolayer films of bi-functional catalysts (PtRu) were deposited on novel nanostructured supporting materials, designed with the goal of achieving high variability of their electronic and chemical properties to influence the catalytic activity of sub-monolayer catalyst. The mesoscopic TiO₂ supporting film formation was investigated using EQCN, voltammetric, and AFM techniques. The conditions for the formation of monodispersed TiO₂ nanoparticles with regular nanopores, 20-80 nm in diameter, were described. It follows from EQCN and voltammetric measurements and AFM image analysis that the nanopores are formed by a dissolution-precipitation mechanism. The activity of submonolayer catalysts PtRu deposited on nanoporous TiO_2-n films was investigated using the point defect formation voltammetry. A lower poisoning effect for cluster PtRu on a TiO₂ support film than that for unsupported PtRu and bare Pt catalysts has been observed. The implications of the support-catalyst interactions are discussed in details.