SYNTHESIS OF PtCo/TiO2 CATALYSTS BY FLAME SPRAY PYROLYSIS FOR SELECTIIVE HYDROGENATION OF FURFURAL TO FURFURYL ALCOHOL

Abstract

The selective hydrogenation of furfural to furfuryl alcohol (FA) was carried out in a batch reactor at 50 ̊C and 20 bar H2 using Pt-Co/TiO2 with 0.5 wt%Pt and 0-0.8 wt%Co. The catalysts were characterized by X-ray diffraction (XRD), N2-physisorption, X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), atomic absorption spectroscopy (AAS), CO-pulse chemisorption and transmission electron microscopy (TEM). Addition of Co into monometallic (I) Pt/TiO2 catalyst increased both furfural conversion and FA selectivity because it prevented anatase to rutile transformation of TiO2 and increased the interaction between metal and TiO2. However, Co adding into monometallic (F) Pt/TiO2 catalyst resulted in a decrease in furfural conversion but increased FA selectivity because during FSP, Co addition accelerated anatase to rutile transformation. A comparison between flame spray pyrolysis and impregnation method showed that, the (F) Pt/TiO2 and (I) Pt/TiO2 catalysts exhibited similar furfural conversion but FA selectivity of the (F) Pt/TiO2 was much higher than the (I) Pt/TiO2 because the (F) Pt/TiO2 catalyst showed stronger interaction between Pt and TiO2 support. For bimetallic catalysts, the Pt-0.2Co/TiO2 catalysts synthesized by impregnation method exhibited the best catalytic performance for selective hydrogenation of furfural to furfuryl alcohol. In summary, hydrogenation activity increased with increasing %anatase in the TiO2 support while FA selectivity depended largely on the strong metal-support interaction.