异丁烯-甲醛一步法制异戊二烯新体系催化剂的研究

对异丁烯-甲醛气相一步法制异戊二烯Cu_xBi_yO_z/SiO_2催化剂活性组份负载量、制备和操作条件进行了考察,并与 Bi_yO_z/SiO_2、Cu_xO_z/SiO_2单活性组份进行比较。结果表明,Bi_yO_z/SiO_2催化剂对该反应几乎没有活性;Cu_xO_z/SiO_2虽有一定的活性但有较长,的诱导期;Cu_(?)Bi_yO_z/SiO_2能消除诱导期,并使反应结果达到较高水平。通过对 Cu_xBi_yO_z/SiO_2操作条件的考察,找出了该催化剂的最佳反应条件:反应温度280—300℃;反应周期50分钟;接触时间0.6秒;烯醛摩尔比6.7。

Investigation of New Catalysts for One-step Condensation of Formaldehyde and Isobutylene to Form Isoprene

The loading level of the active components copper and bismuth,the condi-tions of preparation and the reaction of Cu_xBi_yO_z/SiO_2 catalysts for gas-phase con-densation of formaldehyde and isobutylene to form isoprene have been investigatedand compared with that of single active component Bi_yO_z/SiO_2 and Cu_xO_z/SiO_2.Theresults show that Bi_yO_2/SiO_2 catalyst has much lower catalytic activity for thereaction than Cu_xBi_y O_z/SiO_2 and though Cu_xO_z/SiO_2 catalyst is active,the inductionperiod for the condensation reaction is rather long.Cu_xBi_yO_z/SiO_2 catalyst has noinduction period and has the highest activity.Preferred reaction conditions of Cu_xBi_yO_z/SiO_2 catalyst are as follows:reaction temperatures,280—300℃;reactiontime,50 minutes;contact time,about 0.6 second and the ratio between isobutyleneand formaldehyde,ca.6.7.