α-甲基苯乙烯加氢生成异丙苯Pd/γ-Al_2O_3催化剂制备及评价

Preparation and evaluation of the Pd/γ-Al_2O_3 catalysts for hydrogenation of α-methylstyrene to cumene

用不同的方法制备了一系列的Pd/-γAl2O3和Pd-Ni/-γAl2O3催化剂,并在溢流床反应器中对其-α甲基苯乙烯(AMS)加氢为异丙苯的催化性能进行了评价。结果发现用浸渍沉淀法制备的0.25%Pd/-γAl2O3催化剂性能较佳,在0.7MPa、100℃、空时为17min和氢气放空量为10mL/min～20mL/min的条件下,其AMS转化率近100%,异丙苯的选择性为94%以上。对使用过的催化剂进行了Χ射线衍射、透射电镜、扫描电镜表征和能谱分析的结果表明:催化剂钯颗粒分散均匀,反应500h未见晶粒聚集,钯含量不变。制备的最佳催化剂性能可比工业上应用的进口催化剂,甚至在短的实验测时期内还略优。

A series of Pd/γ-Al2O3 and Pd-Ni/γ-Al2O3 catalysts were prepared by different methods, and their catalytic performances for the hydrogenation of α-methylstyrene （AMS） to cumene were evaluated in an overflow packed bed reactor. It was found that the 0.25%Pd/γ-Al2O3 catalyst prepared by impregnating and then precipitating was optimum. Over this catalyst, AMS conversion was nearly 100% and the selectivity to cumene was over 94% under the conditions of 100℃, 0.7MPa, space time 17 min and hydro- gen venting 10mL/min-20mL/min. The XRD, TEM, SEM and EXS results of the 0.25%Pd/γ-Al2O3 catalyst indicated that the Pd partides was dispersed well, and no aggregation and Pd content change after 500 hours time on stream. The performances of the optimal catalyst could catch up with the import commercial catalyst, and even a little better during the test period.