Low Temperature Toluene And Phenol Abatement As Tar Model Molecules Over Ni-Based Catalysts: Influence Of The Support And The Synthesis Method

Ni addition over two ceria-based mixed oxides (Ce0.63Zr0.33Sm0.04O2- delta, and Ce2Y2O7) has been carried out by sol-gel (Ni-CZS and Ni-CY) and wet impregnation (Ni/CZS and Ni/CY) methods. The four catalysts were characterized by BET, XRD, TGA, XPS, H-2-TPR and H-2-chemisorption. Partial insertion of Ni2+ ions into both mixed oxide's structure was found in the corresponding sol-gel catalysts. Their catalytic activity was evaluated in tar reforming, with toluene and phenol as model molecules, under isothermal condition at 400 and 550 degrees C for 6 h, using a typical ex-biomass syngas composition in order to mimic the real conditions of a gasification process. Among the four materials, Ni/CY was the best catalyst in terms of average tar conversion, whereas the best catalytic stability was obtained for Ni-CZS, owing to inserted Ni2+ species. This study demonstrates that Ni/CY can be a promising system for tar abatement at relatively low temperature through catalytic hot gas cleaning of a raw syngas generated by biomass gasification.