研究了浸渍法制备的V/ZSM-5分子筛催化剂在微波辅助下催化苯直接羟基化制备苯酚的反应.采用XRD,N2物理吸附技术手段考察了催化剂的性质.实验结果表明:500℃煅烧4 h,5 wt%V的负载量制备的催化剂具有更好的催化活性.同时,研究了微波辅助下V/ZSM-5分子筛催化剂在不同的反应时间,催化剂的量,H2O2的量的催化活性.对比常规加热得到苯的转化率19.6%;V/ZSM-5催化剂在微波辅助下得到苯的转化率为32.2%和苯酚的选择性为100%.
The hydroxylation of benzene to phenol over V/ZSM-5 catalysts prepared by impregnated-method was investigated under microwave irradiation. The catalysts were characterized by XRD and N 2 adsorption techniques. This paper indicated the optimal calcined condition for V/ZSM-5 catalysts is 500 oC calcined temperature, 5 h calcined time and 5 w/t%loading of V. Various reaction parameters, such as reaction time, amount of catalyst and hydrogen peroxide were investigated to obtain an optimal reaction conditions for phenol formation under microwave irradiation. Coupled conventionally heated method gives phenol yield of 19.6%, the V/ZSM-5 gives higher phenol yield of 32.2%and selectivity of 100%under microwave irradiation conditions.