EFFECT OF SUPPORT ON THE PERFORMANCE OF PALLADIUM CATALYSTS FOR SELECTIVE HYDROGENATION
Jingping Hong · Acta Petrolei Sinica(Petroleum Processing Section) · 2006
Supported palladium catalysts were elaborated by impregnation method,in an attempt to determine the influences of support pretreatment and species on the activity and the selectivity of acetylene hydrogenation.Among tested Al_2O_3 supports,δ-Al_2O_3 formed under 1100℃ calcination possessed more selectivity of C_2H_4.The MgO or CeO_2 modified Al_2O_3 resulted in the good catalytic performances of catalyst,and the ethylene yield kept about 80% at high volune ratio of H_2 to C_2H_2.In addition,because of the strong palladium-support interaction and the suitable adsorption-desorption properties for reactant and products,the hydrogenation performance of Pd/TiO_2 catalyst was improved much significantly,and the ethylene yield was enhanced to the value of 95%.From the temperature programmed reduction(TPR)and the carbon monoxide desorption(TPR-CO) data,it is indicated that Pd~(b)H_x species on catalyst surface and Pd-C bond strength influenced strongly H_2 adsorption and the ethylene desorption from the catalyst surface.