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

H2H2 with ultra-low CO concentration was produced via photocatalytic reforming of methanol on Au/TiO2Au/TiO2 catalyst. The rate of H2H2 production is greatly increased when the gold particle size is reduced from 10 to smaller than 3 nm. The concentration of CO in H2H2 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 H2H2 and CO2CO2 products while suppress the CO and H2H2O products. In addition, some CO may be oxidized to CO2CO2 by photogenerated oxidizing species at the perimeter interface between the small gold particles and TiO2TiO2 under photocatalytic condition.