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制备了单金属双中心Ti MCM 41分子筛催化剂 ,通过XRD、低温N2 吸附 脱附、XPS及原子吸收光谱等对催化剂进行了表征 .结果表明 ,单金属双中心Ti MCM 41分子筛催化剂具有良好的长程有序结构和孔结构 ,其比表面积大于 10 0 0m2 g ,孔径分布窄 ,最可几孔径为 2 7nm ;Ti的电子结合能为 45 8 6eV ,介于骨架Ti(选择性氧化活性中心 )和非骨架Ti(光催化活性中心 )之间 .以H2 O2 和·OH的生成量为基准 ,考察了Ti MCM 41对苯羟化反应的催化性能随光照时间、催化剂用量、加水量、反应温度和空气流速等条件的变化 ,得出了光催化反应的最佳条件 .在无外加氧化剂的情况下 ,单金属双中心Ti MCM 41上苯的转化率为 0 2 % ,表明其确实具有一定的光催化性能 ,可实现光催化 选择性氧化的反应 反应耦合 .与骨架取代Ti MCM 41和MCM 41负载TiO2 催化剂相比 ,单金属双中心Ti MCM 41的催化活性最高 .这主要是由于它既具有光催化活性中心 ,又具有选择性氧化活性中心
The catalyst was characterized by XRD, N2 adsorption and desorption, XPS and atomic absorption spectroscopy. The results showed that the single-metal double-site Ti MCM 41 molecular sieve catalyst has good long-range The pore structure is narrow and the most probable pore size is 27 nm. The electron energy of Ti is 45 8 6 eV, which is between the framework of Ti (selective oxidation activity center) and non The catalytic activity of Ti MCM 41 with respect to the benzene hydroxylation was investigated with the illumination time, the amount of catalyst, the amount of water added, the reaction temperature and the air Flow rate and other conditions, obtained the best conditions for the photocatalytic reaction in the absence of additional oxidants, the single-metal double center Ti MCM 41 benzene conversion was 0.2%, indicating that it does have some photocatalytic Performance, enabling photocatalytic selective oxidation of the reaction-reactive coupling.The single-metal double-site Ti MCM 41 has the highest catalytic activity compared to the framework-substituted Ti MCM 41 and MCM 41 supported TiO 2 catalysts It is due to the photocatalytic activity center, and having a selective oxidation active center