H2 production with ultra-low CO selectivity via photocatalytic reforming of methanol on Au/TiO2 catalyst

H 2 with ultra-low CO concentration was produced via photocatalytic reforming of methanol on Au / TiO 2 catalyst. The rate of H 2 production is greatly increased when the gold particle size is reduced from 10 to smaller than 3 nm. The concentration of CO in H 2 decreases with reducing the gold particle size of the catalyst. It is suggested that the by-product CO is mostly produced via decomposition of the intermediate formic acid species derived from methanol. The smaller gold particles possibly switch the HCOOH decomposition reaction mainly to H 2 and CO 2 products while suppress the CO and H 2 O products. In addition, some CO may be oxidized to CO 2 by photogenerated oxidizing species at the perimeter interface between the small gold particles and TiO 2 under photocatalytic condition.