Gold-iridium catalysts for the hydrogenation of biomass derived products

Au-Ir and Au-Ru on TiO2 catalysts prepared by sequential deposition-precipitation technique were compared with the corresponding monometallics in the hydrogenation of levulinic acid to y-valerolactone. Interestingly the addition of Au to Ir/TiO2 showed a detrimental effect on the activity of Ir monometallic catalyst whereas a positive synergistic effect was shown in the case of Ru. Both catalysts were reduced under H-2 to increase the M-0-Au-0 interaction. From previous DFT calculations and catalytic test, we addressed the lower activity of Au-Ir/TiO2 than that of Ir/TiO2 to the interference of Au into the redox mechanism of Ir atoms. (C) 2016, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.