【摘要】 研究了PMO-SBA-15材料负载的金属钯纳米粒子(Pd/PMO-SBA-15)在水相中催化苯甲醇选择氧化制苯甲醛的反应.考察了纳米粒子种类、氧化剂用量、反应时间和反应温度等对苯甲醇转化率及苯甲醛选择性的影响.结果表明,以水为溶剂,以H2O2(30%)为氧化剂时,可得到较高的苯甲醇转化率和苯甲醛选择性.当以0.05g的2%Pd/PMO-SBA-15为催化剂,H2O2用量为1.5ml,反应温度为80oC,反应4h时,苯甲醇转化率和苯甲醛选择性分别达到97.1%和100.0%.对该催化体系的重复使用性能进行了考察.结果发现,随着使用次数的增加,苯甲醇转化率有所下降,但苯甲醛选择性保持不变.更多还原

【Abstract】 Pd nanoparticles were successfully captured by tetraimine groups incorporated into the channel of periodic mesoporous organosilica(PMO-SBA-15),yielding a Pd-containing mesoporous organosilica catalyst(Pd/PMO-SBA-15).N2 adsorption-desorption,X-ray diffraction,and transmission electron microscopy confirmed that the Pd nanoparticles were well stabilized and dispersed uniformly inside the channel of the PMO with average particle size of 1.8 nm.The Pd/PMO-SBA-15 was used as a catalyst for selective oxidation of benzyl alcohol with H2O2 as oxidant in water.The effects of various nanoparticles,H2O2 amount,reaction temperature,and reaction time on the oxidation were investigated.The benzyl alcohol conversion of 97.1% with the selectivity for benzaldehyde of 100.0% was obtained when the reaction was carried out in water with 0.05 g of 2%Pd/PMO-SBA-15 and 1.5 ml of H2O2 at 80 oC for 4 h.Furthermore,the Pd/PMO-SBA-15 could be conveniently recovered for recycle use.The conversion of benzyl alcohol decreased with the increase of reuse times.更多还原