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以微孔分子筛NaY为载体,SnCl_4·5H_2O为锡源,通过液固相同晶取代法制备催化材料Sn-NaY,研究了脱铝预处理和焙烧两个因素对制备Sn-NaY的影响.采用FT-IR、UV-Vis、XRD、N_2物理吸附、ICP、NH_3-TPD、吡啶红外、激光拉曼等手段对催化材料进行了表征.结果表明:对载体进行脱铝预处理有利于分子筛在催化剂制备过程中保持良好的骨架结构,焙烧有利于进入分子筛骨架中的Sn(Ⅳ)与硅羟基成键,从而形成有催化活性的四配位的Sn(Ⅳ),而空气氛围下焙烧容易产生骨架外SnO_2物种.Sn-NaY催化环己酮Baeyer-Villiger氧化结果表明,在环己酮0.03 mol,n(H_2O_2)∶n(酮)=1.5∶1,0.35 g催化剂,15 mL乙腈,70℃反应24 h的工艺条件下,N_2氛围焙烧的同晶取代脱铝催化剂性能最好,环己酮的转化率可达44%,己内酯的选择性为62%.
The Sn-NaY catalyst was prepared by liquid-solid isomorphous substitution method using NaY as carrier and SnCl4 · 5H2O as the source of tin, and the effects of pretreatment and calcination on Sn-NaY were studied. FT- The results showed that the pretreatment of dealumination was beneficial to the preparation of the catalyst in the preparation of the catalyst In the process, Sn (Ⅳ) is bonded with silanol groups to form a catalytically active tetrahedral Sn (Ⅳ) by calcination, which is favorable for roasting to form Sn (Ⅳ) with tetrahedral coordination sites in the molecular sieve framework. SnO_2 species.The results of Baeyer-Villiger oxidation of cyclohexanone catalyzed by Sn-NaY showed that when cyclohexanone 0.03 mol, n (H 2 O 2): n (ketone) = 1.5:1, 0.35 g catalyst, 15 mL acetonitrile, h, the isomorphous substituted de-alumination catalyst calcined at N2 atmosphere has the best performance. The conversion of cyclohexanone reaches 44% and the selectivity of caprolactone is 62%.