Preparation Of Loaded Catalysts Loaded On Silica Gel Microsphere And The Technology Of Benzene Hydroxylation

The method of synthetizing phenol by oxidating benzene has a short process and high atomic economy, which is widely researched. The method of synthetizing phenol by oxidating benzene with hydrogen peroxide as oxidant has only H₂O as by-product, according with the green chemistry, which is a research hotspot. The key point is to choose catalyst with high efficiency. The catalyst can improve effective utilization of H₂O₂ and the yield of phenol. Two kinds of catalysts researched mostly are metallic oxide and molecular sieves.In this paper, the catalysts are prepared after Fe-Cu metallic complex compound and TS-1 molecular sieve loaded on silica gel microsphere with partical size 2⁴mm. the prepared catalysts not only have as high catalytic activity as the catalysts before loaded, but also can be reused, which can reduce the product cost and are important for industrialized application.According to the results of the reaction of synthetizing phenol by oxidating benzene with H₂O₂, the synthetizing condition of the two kinds of catalysts have been researched. The research showed that TS-1/ silica gel microsphere has high catalytic activity on the condition as follows: n(TEOS):n(TBOT):n(TPAOH):n(H₂O)= 1:0.013:0.18:0.45, after removing alcohol, then soaking silica gel microsphere into the solution, crystallization temperrture 160℃, crystallization time 72h, calcination temperrture 550℃, calcination time 6h. the techonology of synthetizing phenol by oxidating benzene catalyzed by TS-1/ silica gel microsphere has been researched. On the condition of the initial material content of benzene 0.5mol and hydrogen peroxide 0.1mol , catalyst 8g, the reaction temperature of 60℃and the reaction time 3h, the conversation of benzene was 10.32% and the selectivity of phenol was 97.12%. After recycling of 9 times, the conversation of benzene and the selectivity of phenol were 9.42% and 93.14% respectively.The synthetizing condition of the Fe-Cu/ silica gel microsphere have been researched. The research showed that the catalyst showed high catalytic activity on the condition of Cu(NO3)2·3H₂O 0.02mol, the mole ratio of Fe/Cu 7/1,the amounts of ammonia making metal ion precipitate rightly and thoroughly, ageing time 72h, calcination temperature 550℃and calcination time 6h. The techonology of synthetizing phenol by oxidating benzene catalyzed by Fe-Cu / silica gel microsphere has been researched. On the condition of benzene 0.2mol, acetonitrile as the solvent, catalyst 20g, hydrogen peroxide 0.1mol and reaction temperature 60℃. After 3h reaction time ,the conversion of benzene reached 15.49 % and the selectivity of phenol reached 94.63 %. After recycling of 6 times, the conversation of benzene and the selectivity of phenol were 13.87 % and 92.56 % respectively.