Study of PtO(x)/TiO(2) Photocatalysts in the Photocatalytic Reforming of Glycerol: The Role of Co-Catalyst Formation

In this study, relationships between preparation conditions, structure, and activity of Pt-containing TiO(2) photocatalysts in photoinduced reforming of glycerol for H(2) production were explored. Commercial Aerolyst(®) TiO(2) (P25) and homemade TiO(2) prepared by precipitation-aging method were used as semiconductors. Pt co-catalysts were prepared by incipient wetness impregnation from aqueous solution of Pt(NH(3))(4)(NO(3))(2) and activated by calcination, high temperature hydrogen, or nitrogen treatments. The chemico-physical and structural properties were evaluated by XRD, (1)H MAS NMR, ESR, XPS, TG-MS and TEM. The highest H(2) evolution rate was observed over P25 based samples and the H(2) treatment resulted in more active samples than the other co-catalyst formation methods. In all calcined samples, reduction of Pt occurred during the photocatalytic reaction. Platinum was more easily reducible in all of the P25 supported samples compared to those obtained from the more water-retentive homemade TiO(2). This result was related to the negative effect of the adsorbed water content of the homemade TiO(2) on Pt reduction and on particle growth during co-catalyst formation.