Promoter effect of Ga in Pt/Ga-TiO 2 catalysts for the photo-production of H 2 from aqueous solutions of ethanol

In this paper, the effect of Ga in Pt/Ga-TiO2 catalysts for photocatalytic H2 production from aqueous solutions of ethanol is studied. The fresh and post-reaction catalysts were characterized using different techniques including BET, XRD, TPR, SEM-EDX, XPS, CO chemisorption and in situ DRIFTS. The presence of Ga in Pt/TiO2-based catalysts increased the Pt dispersion and decreased the relative amount of surface oxidized Pt species. Pt/Ga-TiO2 catalysts showed more stable behaviour during the photocatalytic reaction than the reference Pt/TiO2. The Pt/0.2Ga-TiO2 catalyst showed a higher initial rate of production of H2 and produced a higher total amount of H2 than the monometallic Pt/TiO2. The promoter effect of Ga is analysed in the light of the surface characteristics of the catalysts.