纳米Au-Pd@Ce修饰介孔磷酸铝的制备及其催化氧化环己烷性能

Preparation of Au-Pd@Ce modified mesoporous aluminum phosphates and their catalytic performances for selective oxidation of cyclohexane

采用水热合成法制备Ce修饰介孔磷酸铝,再通过原位还原法负载纳米Au-Pd制备催化剂;通过以空气为氧化剂的环己烷选择性氧化反应测试催化剂的催化性能,并考察水热温度、Ce掺杂量、负载贵金属对催化剂催化氧化环己烷的的影响。结果表明,以140℃水热制备的Ce掺杂质量分数为0. 15%的Ce0. 15-APO(140)负载Au-Pd双金属(Au与Pd质量比3∶1)催化剂活性最高。在反应温度120℃,空气压力1 MPa和反应1 h的条件下,环己醇+酮的产率可达11. 81%,选择性达99%,催化剂在同样条件下循环使用5次,活性无明显下降。

Cerium modified mesoporous aluminum phosphate(Ce-APO)was prepared by hydrothermal synthesis,and then nanometric dual noble metal Au-Pd was supported on Ce-APO via a in situ reduction method to obtain supported Au-Pd@Ce-APO heterogeneous catalyst.All the prepared catalysts were tested in selective oxidation of cyclohexane with air as oxidant.Effects of hydrothermal temperature,doping amount of Ce,and loaded metal on catalytic oxidation of cyclohexane were investigated.Results suggested that Ce 0.15-APO(140)with Ce mass fraction of 0.15%supported bimetallic[n(Au)∶n(Pd)=3∶1]catalyst prepared under hydrothermal temperature of 140℃was most effective among all the catalysts.Under the reaction conditions of 120℃,1 MPa of air pressure,and 1 hour of reaction time,yield of cyclohexanol+ketone could reach 11.81%,and selectivity could reach 99%.Activity did not decrease obviously after used under the same condition for 5 cycles.