Al_2O_3负载Pd-Cu催化剂催化1,2-二氯乙烷加氢脱氯性能

Catalytic hydrodechlorination of 1,2-dichloroehtane over Pd-Cu/γ-Al_2O_3 catalysts

采用共浸渍法制备了一系列Al2O3负载金属Pd、Cu催化剂.通过元素分析(ICP)、氮气吸脱附(BET)、X射线粉末衍射(XRD)、透射电镜(TEM)等技术对催化剂进行了表征,并以1,2-二氯乙烷气相加氢脱氯为探针反应,考察了Pd-Cu/Al2O3催化剂的钯铜比、反应温度、反应时间等因素对催化活性以及反应产物乙烯选择性的影响.结果发现,提高Cu负载量可在催化剂中形成Pd-Cu合金,并促进催化剂对乙烯的选择性.此外,当温度为250℃,Pd、Cu负载量分别为0.78%和1.9%时的Pd-Cu/Al2O3催化剂对1,2-二氯乙烷的催化加氢脱氯效果最佳,最终产物乙烯的选择性可达到80%以上.

Pd-Cu/γ-Al2O3 catalysts with various metal loadings were prepared by the co-impregnation method,and were characterized by elemental analysis,X-ray powder diffraction,N2 adsorption and transmission electron microscopy.The catalysts were used for the gas phase catalytic hydrodechlorination of 1,2-dichloroehtane.The effects of Pd/Cu ratio,reaction temperature and reaction time on 1,2-dichloroehtane conversion and ethylene selectivity were tested.The results indicate that increasing Cu loading lead to the formation of palladium-copper alloy and enhanced ethylene selectivity.Furthermore,at 250 ℃,the bimetallic catalyst with 0.78% Pd and 1.9% Cu exhibited optimum catalytic behavior,with an ethylene selectivity higher than 80%.