【作者】 王庆法；

【导师】 王莅；

【作者基本信息】 天津大学 ， 化学工艺， 2004， 硕士

【摘要】 环氧氯丙烷是一种重要的有机化工原料和中间体,当前的生产方法存在污染严重,成本高、能耗大等问题。使用过氧化氢做氧化剂环氧化烯烃制备环氧化合物的方法,虽具有选择性高、过程清洁无污染的特点,但过氧化氢成本高,并且储存和运输困难,使得该过程很难进一步发展,因此急需开发新型的生产途径。将环氧化反应与氢氧直接合成过氧化氢耦合是烯烃环氧化反应研究的方向和热点。基于此,本文对氢氧原位合成过氧化氢和氯丙烯环氧化反应的集成过程进行了研究。考察了溶剂、温度和过氧化氢浓度对氯丙烯环氧化反应的影响,发现甲醇是氯丙烯环氧化反应的最佳溶剂,在常温和过氧化氢浓度较低的情况下,该反应体系仍能得到较高的环氧氯丙烷收率。在上述研究基础上,分别以 Pd 和 Au 作为合成过氧化氢的活性组分,TS-1作为环氧化反应的活性组分制备了双功能催化剂,考察了制备方法、钯源、还原条件、金属负载量、Pt 助剂对催化剂性能的影响。结果表明:以氯化钯为钯源,采用沉淀沉积法制备催化剂,在 150℃、5%H2/95%N2的气氛中进行还原得到的催化剂性能较好。对于钯催化剂,负载量以 1wt%为宜,而金催化剂以 2 wt%为宜。加入 Pt 助剂,能提高钯催化剂的催化性能,其加入量以 0.01 wt%~0.02 wt%为佳。对催化剂进行 XPS,TPD-TPR,TEM 等研究发现,加入 Pt 后提高了钯的分散度和结合能,从而提高了催化性能。0.01%Pt-1%Pd/TS-1 的催化效果最好。在0.01%Pt-1%Pd/TS-1催化下对氢氧原位合成过氧化氢和环氧化氯丙烯制备环氧氯丙烷的集成过程进行了研究,考察了溶剂、反应时间、催化剂浓度和氯丙烯初始浓度对集成过程的影响。结果表明以 30wt%的醇-水溶液为溶剂,在反应时间为 4h,催化剂浓度 15g/L 氯丙烯/甲醇=0.15:1(摩尔比)的条件下,环氧氯丙烷的收率和选择性分别为 0.6%和 0.7%.最后,考察了制备方法和 Pt 助剂对 TS-1 催化氯丙烯环氧化反应的影响。结果表明负载的贵金属对过氧化氢具有明显的分解作用,Pt 助剂的加入能部分提高催化剂的环氧化能力。XRD 和 FTIR 分析结果表明,在负载过程中,钛硅分子筛的结晶度下降,并伴有一定的钛流失,这些是负载贵金属后 TS-1 催化剂环氧化能力下降的主要原因。更多还原

【Abstract】 Epichlorohydrin(ECH) is an important chemical material and intermediate. Inpresent, the production techniques of ECH have some distinct disadvantages, such assevere pollution, high cost and high-energy consumption. The process of epoxidationof low olefins with H2O2 catalyzed by TS-1 has the advantages of high selectivity andno pollution. Because of the relatively high cost of H2O2 and the transportation andstorage of hydrogen peroxide, this process has not been commercialized up to date. Inorder to overcome the economic obstacle, the integration of the production ofhydrogen peroxide and the epoxidation of olefins is the research orientation of olefinepoxidation. Based on this, the integrated process of production of hydrogen peroxideand epoxidation of allyl chloride has been studied in this thesis.The effects of different solvent, temperature and concentration of hydrogenperoxide on epoxidation of allyl chloride with H2O2 using TS-1 were investigated.Under the room temperature and low concentration of hydrogen peroxide, relativelyhigh yield of ECH was still obtained. Methanol is the optimal solvent for theepoxidation of allyl chloride.Based on above experimental results, the dual-functional catalysts were preparedby taking Pd and Au as the active components for producing hydrogen peroxide fromhydrogen and oxygen and TS-1 as the active component for epoxidation of allylchloride. The effects of preparation methods of catalysts, Pd precursors, reductioncondition, metal loading and Pt supporter on the catalytic performance wereinvestigated. The results indicated that the catalysts made by DP method, usingpalladium chloride as Pd precursor and reduced by 5%H2/95%N2 under 150℃ hasexcellent catalytic performance. The metal loading of 1 wt% for Pd and 2 wt% for Auis optimum. The addition of Pt to Pd/TS-1 catalyst could remarkably improve thecatalytic performance. The optimal loading of Pt is 0.01 wt%~0.02 wt%. The resultsof XPS, TPD-TPR, and TEM indicated that the dispersion and Binding Energy (BE)of palladium supported on TS-1 had been improved by introducing small amount ofPt, and the catalytic performance has been dramatically improved. In view of theabove experimental results, the 0.01%Pt-1%Pd/TS-1 is the optimal catalyst for theprocess integration in our work. The integrated process of producing hydrogenperoxide from hydrogen and oxygen and producing ECH by epoxidation of allyl<WP=5>chloride has been studied over the 0.01%Pt-1%Pd/TS-1. The effects of differentsolvent, reaction time, catalyst concentration and initial concentration of allyl chloridewere investigated and the optimal experimental condition were the methanol solutioncontaining 30 percent of water as solvent, 4h, 15g/L and the initial molar ratio of allylchloride to methanol at 0.15:1. Under these conditions, the yield and selectivity ofECH were 0.6% and 0.7%, respectively.Finally, the effects of preparation method and addition of Pt supporter onepoxidation reaction of allyl chloride with H2O2 over Pd/TS-1 catalyst wereinvestigated. The experimental results indicated that the noble metal has a dramaticimprovement to the decomposition of hydrogen peroxide. The addition of Ptsupporter could improve the epoxidation of allyl chloride. The results of XRD andFTIR of dual-function catalyst indicated that the crystal phase structure of TS-1 hadbeen damaged to some extend and the crystallinity of TS-1 decreased, and Ti leachingoccurred in the course of catalyst preparation. These parameters are the main causesto decrease the epoxidation activity of TS-1 catalysts.更多还原