As an alternative process to petroleum based processes

hydrogenolysis of biomass-derived glycerol to 1

3-propanediol (1

3-PD) can be effectively catalyzed by bimetallic Ir-Re catalyst. However it still suffers from low selectivity of 1

3-PD and low reaction rate. With extension of our previous study

silica was selected as a promising catalyst support to investigate the role of silica chemistry in the Ir-Re catalyst for glycerol hydrogenolysis. Bimetallic Ir-Re catalysts supported on three kinds of silica supports of KIT-6

G-6 and FS were prepared for glycerol hydrogenolysis to produce desired 1

3-PD. The structure of catalysts were characterized by varied techniques of N2 adsorption-desorption

transmission electron microscopy (TEM)

X-ray diffraction (XRD)

H2 temperature-programmed reduction (H2-TPR)

in-situ CO adsorption diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) of ammonia. Also

the structure-activity relationship of the catalysts was discussed. It showed that the bimetallic catalysts on three silica supports possessed alloy structure of Ir-Re on surface

of which the order of alloy degree follows Ir-Re/KIT-6 > Ir-Re/FS > Ir-Re/G-6. Hydroxyl groups on support surfaces significantly affected the degree of metal dispersion and the interaction between active metallic components and support. The Ir-Re/FS catalyst possessed the highest degree of metal dispersion and exhibited the best initial activity but the worst stability for glycerol hydrogenolysis

while the Ir-Re/KIT-6 catalyst featured the highest degree of alloy thus showed excellent catalytic performance and the highest selectivity to 1

3-PD of desired product.