双功能催化剂中金属铂对乙苯异构化反应的影响

以丝光沸石为催化剂的酸性组元,制备了负载铂的C_8芳烃异构化双功能催化剂;在连续流动临氢微型固定床反应装置上考察了双功能催化剂中金属铂对乙苯异构化反应的影响,着重考察了金属铂的负载量、负载方式、分散度以及铂负载量与酸量的匹配等因素对催化剂性能的影响。实验结果表明,随铂负载量的增加,乙苯转化率增大,异构化选择性先增大后减小,在铂质量分数为0.45%时达到最大值;在催化剂的酸量一定时,铂负载量有一适宜的范围,即适宜的铂原子数量与酸性中心数量的比值(Nm/Na值),对于硅铝比为11.1的丝光沸石,适宜的铂负载量为0.30%～0.45%,,当Nm/Na值为0.26时,异构化选择性最大;与铂络合物离子交换法相比,浸渍法制备的催化剂性能较好;铂分散度在50%～70%时,催化剂的综合性能较好。

Effect of Platinum in Bifunctional Catalyst on Ethylbenzene Isomerization

Pt supported bifunctional catalysts with mordenite zeolite as acid function units,which were used in C_8 aromatics isomerization,were prepared and their activities in ethylbenzene(EB) isomerization were evaluated in a fixed bed reactor.Effects of the Pt content,loading method,the Pt dispersion degree and number ratio of the Pt atom to the acid sites in the catalyst(Nm/Na) on the EB isomerization were studied.The results indicated that with the increase of the Pt content,the EB conversion rose,the isomerizat...