CO2 Reforming of Toluene from Biomass Tar over Ni/Palygorskite Catalyst

A nickel catalyst supported on palygorskite (PG) with large surface area was prepared by equal volume impregnation. Catalytic reforming of biomass tar over Ni/PG was studied using toluene as the model compound in the presence of CO2. X-ray diffraction, transmission electron microscopy and CO2-temperature programmed desorption were used to characterized the catalyst samples. The influence of CO2 amount, reaction temperature, and Ni loading on toluene conversion, hydrogen yield, and carbon deposit was investigated. The results showed that three desorption peaks of CO2 appeared on both PG and the Ni/PG catalyst. The toluene conversion and H-2 yield increased with the increase in the amounts of CO2 and Ni content as well as the reaction temperature. At 800 degrees C and CO2/PhCH3 molar ratio of 0.2-0.26, the toluene conversion was the highest; the H-2 yield reached the highest at CO2/PhCH3 molar ratio of 0.2. Carbon deposition decreased with increasing the CO2 amount and reaction temperature.