氧化铼负载于介孔氧化铝催化剂丁烯歧化性能

Metathesis of butene over rhenium oxide supported on mesoporous alumina

用溶胶-凝胶法合成介孔氧化铝(meso-Al2O3)载体,浸渍Re2O7后制备了一系列Re2O7/meso-Al2O3催化剂,研究了Re2O7负载量对催化剂物化性质的影响,考察了Re2O7/meso-Al2O3催化剂在1-丁烯与2-丁烯歧化反应中的性能,并与Re2O7/γ-Al2O3催化剂进行了对比。表征结果表明:随着Re2O7负载量的增加,Re2O7/meso-Al2O3催化剂的BET比表面积和孔体积逐渐减小,酸量逐渐增多;铼基催化剂几乎只存在L酸;与Re2O7/γ-Al2O3催化剂相比,Re2O7/meso-Al2O3催化剂的L酸量更多、酸性更强。Re2O7/meso-Al2O3催化剂在丁烯歧化制丙烯反应中表现出优异的催化性能,在反应温度60℃、质量空速1h-1、常压的反应条件下,丁烯初始转化率约为54%,优于传统的Re2O7/γ-Al2O3催化剂。当m(Re2O7)∶m(Al2O3)为0.2时,Re2O7/meso-Al2O3催化剂歧化性能最佳,丙烯选择性维持在55%左右,稳定时间约为120h。

Re2O7/meso-Al2O3 catalysts with different Re2O7 loadings were prepared by wetness impregnation of Re2O7 on mesoporous alumina.The catalytic performance of the catalysts was also investigated,and compared with Re2O7/γ-Al2O3 catalyst.The results showed that with the increase of Re2O7 loading,the BET surface area and pore volume of the catalysts decreased while the acid amount increased.The metathesis catalyst was prepared by impregnation under the conditions of 60℃,1 h-1 and atmospheric pressure,and the initial conversion of butene was about 54%,by using Re2O7/meso-Al2O3 as the catalyst.The Re2O7/meso-Al2O3 with m（Re2O7）∶m（Al2O3）=0.2 exhibited the best catalytic performance of olefin metathesis among the Re2O7/meso-Al2O3 catalysts.The reaction selectivity of propylene was about 55%,and the life-time of catalyst was 120 h.