研究了苯过氧化氢直接羟基化制备苯酚反应中不同种类助剂对高铜含量(最高达26.0%)MCM-41催化性能的影响.结果表明,掺杂酸性助剂B和Al可使苯酚的选择性达到100%,氧化还原性助剂V和Cr可适当提高苯转化率,而Zr和Ti等元素对Cu-MCM-41的催化性能有抑制作用.根据自由基反应机理对不同助剂产生的影响进行了初步分析.
Cu-MCM-41 with a high copper content up to 26.0% showed excellent catalytic activity in the direct hydroxylation of benzene with hydroperoxide. The effects of various kinds of heteroatoms on the catalytic activity were studied. The introduction of a small amount of acidic promoters such as B and Al can enhance phenol selectivity to 100%. Some redox promoters such as V and Cr increase the conversion of benzene slightly, whereas other elements such as Ti and Zr inhibit the catalytic activity of catalysts. The reasons for these influences were briefly discussed according to the radical mechanism.