Hydrogen production by photoreaction of ethanol over Au/TiO_2anatase. Theeffect of TiO_2particle size.

摘要

The work presents the photo-catalytic reactions of ethanol over Au particles deposited onTiO_2anatase nano- (≤10 nm) and micro- (ca. 0.15 pm) particle catalysts. TheAuparticlesare of uniform and similar dimension (mean particle size = ca. 5 nm and 7 nm on the micro-and nano-sized TiO_2, respectively).XPS Au4findicated that in both casesAuparticles arepresent in their metallic state with no evidence of charge transfer to (or from) thesemiconductor. Liquid slurry photoreaction indicated the production of hydrogen with a rate 2 L/kgcatai.min on 2 wt. % Au/TiO_2anatase nano-particles under UV photo irradiation ofcomparable intensity to solar radiation. While the reaction rate per unit mass was lower onthe micro-sized Au/TiO_2it simply scaled up to an equivalent rate for the nano-sizedAu/TiO_2catalyst when normalised by unit area.