关键词: 碱性助剂, Pd催化剂, 选择性加氢, 氧化铝, 氧化钛, 丁二烯, 炔烃

Abstract: Catalyst support was modified by alkaline additive using impregnation and wet-kneading methods respectively, and the relative Pd/Al2O3-TiO2 catalysts were prepared by impregnation method. The samples of catalyst and support were characterized by BET, XRD, NH3-TPD and Py-IR techniques. The activities of the prepared catalysts for alkyne selective hydrogenation were evaluated using alkyne containing C4 fraction as feedstock. Results showed that the modification methods had little influence on the crystal phase structure of support. However, the pore volume, average pore size and most probable pore size of the support modified by wet-kneading method were all larger than those of support modified by impregnation, the total acid amount and the strong/medium acid amount of the former were less, which would be helpful to improve the selectivity and stability of the prepared hydrogenation catalyst. Catalyst prepared by using support from wet-kneading method exhibited a alkyne conversion of 73%, the selectivity to butadiene and the loss of butadiene were 85% and 2.5%, respectively, its selectivity was better than that of catalyst without modification.

Key words: Alkaline additive, Pd Catalyst, Selective Hydrogenation, alumina, titania, butadiene, alkyne