Photocatalytic hydrogen production by reforming of methanol using Au/TiO2, Ag/TiO2 and Au-Ag/TiO2 catalysts

We have investigated polyvinylalcohol stabilized Au and Ag based nanoparticles supported on titania prepared via sol immobilisation for the anaerobic, ambient temperature reforming of methanol with water for the photocatalytic production of hydrogen. The catalytic activity of the Au/TiO<inf>2</inf> catalysts was strongly affected by the metal loading and calcination temperature. Here, we report the preparation and use of supported Au–Ag nanoparticles, based on either the co-reduction or the consecutive reduction of the two metals. Au–Ag supported catalysts were more active than monometallic Au and Ag catalysts and the preparation methodology had a pronounced effect in terms of catalytic activity of the Au–Ag catalysts. In fact, using a consecutive reduction where Au was firstly reduced followed by reduction of Ag gave materials which exhibited the highest catalytic performance.