Hydrogen production by photoreaction of ethanol over Au/TiO2 anatase. The effect of TiO_2 particle size.

摘要

The work presents the photo-catalytic reactions of ethanol over Au particles deposited on TiO_2 anatase nano- (≤ 10 nm) and micro- (ca. 0.15 μ.m) particle catalysts. The Au particles are of uniform and similar dimension (mean particle size = ca. 5 nm and 7 nm on the micro-and nano-sized TiO_2, respectively). XPS Au4f indicated that in both cases Au particles are present in their metallic state with no evidence of charge transfer to (or from) the semiconductor. Liquid slurry photoreaction indicated the production of hydrogen with a rate ≈ 2 L/kgcatai-min on 2 wt. % Au/TiO_2 anatase nano-particles under UV photo irradiation of comparable intensity to solar radiation. While the reaction rate per unit mass was lower on the micro-sized Au/TiO_2 it simply scaled up to an equivalent rate for the nano-sized Au/TiO_2 catalyst when normalised by unit area.