Hydrogen photoevolution from water-methanol on Ru/TiO2

“In situ” ruthenium photodeposition on anatase TiO2 was found to be an efficient method of obtaining Ru/TiO2 powders highly active in hydrogen photoevolution from water-methanol. The efficiency of the catalyst was higher when the TiO2 powder was subjected to a cation exchange prior to illumination in water-methanol. Reaction conditions were optimized; it was found that the most active sample was TiO2 covered with 0.75 wt% Ru. Anatase TiO2 itself was found to be porous with an average cylindrical pore radius of 37 A. SEM and electron microprobe analysis showed that the photodeposition of ruthenium on the porous substrate resulted in a nonhomogeneous distribution on the TiO2 surface. The size of ruthenium islets seems to influence the stability of Ru/TiO2 catalysts in hydrogen photoevolution from water-methanol.