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对钛硅分子筛TS1催化环己酮氨氧化制环己酮肟的研究结果表明,提高催化剂的投料量、提高分子筛的钛硅比和降低H2O2的空速,有利于提高氨氧化反应的转化率和选择性.降低氨/酮比不利于氨氧化反应,适宜的氨/酮摩尔比应该在20以上.适宜的氨氧化反应温度是80℃左右,过低和过高的温度都不利于氨氧化反应.进料方式会严重影响TS1催化氨氧化反应:H2O2的连续进料和氨的间歇进料方式可获得最佳的结果.在优化的反应条件下,环己酮的转化率可达100%,环己酮肟的选择性为97%.给出了可能的TS1催化氨氧化反应机理,认为氨氧化反应是经历了氨催化氧化为羟胺的过程,肟是羟胺与环己酮通过非催化方式直接反应的结果.
The results of the catalytic oxidation of cyclohexanone to cyclohexanone oxime by cyclohexanone catalyzed by TS1 show that increasing the catalyst loading, increasing the ratio of titanium to silicon and decreasing the space velocity of H2O2 are beneficial to the conversion of ammonia oxidation reaction Rate and selectivity. Lower ammonia / ketone ratio is not conducive to ammonia oxidation reaction, the appropriate ammonia / ketone molar ratio should be 2 0 above. Appropriate ammonia oxidation reaction temperature is about 80 ℃, too low and too high temperature are not conducive to ammonia oxidation reaction. The feeding method will seriously affect the TS 1 catalytic ammoxidation: continuous feeding of H2O2 and intermittent feeding of ammonia can get the best results. Under optimized reaction conditions, the conversion of cyclohexanone reached 100%, and the selectivity of cyclohexanone oxime was 97%. The possible mechanism of ammoxidation catalyzed by TS1 is given. It is believed that the ammoxidation undergoes the catalytic oxidation of ammonia to hydroxylamine, and the oxime is the result of the direct reaction of hydroxylamine and cyclohexanone by a non-catalytic method.