有机官能化介孔硅基材料负载纳米金催化剂的制备及其催化性能

Preparation and Catalytic Performance of Gold Nanoparticles Supported on Periodic Mesoporous Organosilica of SBA-15

一步合成了桥键嵌入二硫醚官能化介孔硅基材料(PMO-SBA-15),利用介孔硅基材料孔道内表面的二硫醚基团捕获纳米金(Au)粒子的作用,获得了负载型纳米Au催化剂(Au-PMO-SBA-15).小角X射线衍射和低温N2吸附-脱附的结果表明,PMO-SBA-15和Au-PMO-SBA-15均保持典型的介孔结构;高分辨透射电镜观察到纳米Au粒子在载体孔道内分散均匀,平均粒径为(2.2±0.2)nm.以70%的叔丁基过氧化氢水溶液为氧化剂,考察了纳米Au催化剂Au-PMO-SBA-15在苯甲醇氧化反应中的催化性能.结果表明,当反应温度为353K、反应时间为5h时,苯甲醇的转化率为29.1%,苯甲醛的选择性为100%,且催化剂重复使用7次其催化活性和苯甲醛选择性基本不变.

A functionalized periodic mesoporous organosilica, PMO-SBA-15, incorporated with bridging disulfide groups was synthesized via a one-pot process. The use of disulfide groups in the channels of PMO-SBA-15 to capture gold nanoparticles （GNPs） yielded a stable mesoporous organosilica-supported gold catalyst （Au-PMO-SBA-15）. X-ray diffraction and N2 adsorption-desorption results showed that both PMO-SBA-15 and Au-PMO-SBA-15 maintained the typical characteristics of the mesoporous material. High-resolution transmission electron microscopy images indicated that GNPs highly dispersed in the channels of Au-PMO-SBA-15 possessed a mean size of （2.2±0.2） nm. The catalytic performance of Au-PMO-SBA-15 in the selective oxidation of benzyl alcohol by aqueous t-butyl hydroperoxide was investigated. A benzyl alcohol conversion of 29.1% with 100% selectivity for benzaldehyde can be obtained when the reaction was conducted at 353 K for 5 h. Furthermore, Au-PMO-SBA-15 can be conveniently recovered and recycled 7 times without significant loss of activity and selectivity.