CAJ | 학술논문

以层状 MCM-22P 为前驱体,四甲基铵硅酸盐为柱化剂,采用动态水热法考察了 MCM-36分子筛的合成条件,并通过XRD、N2物理吸附、TEM、27 Al-MAS NMR 以及 NH3-TPD 等手段对合成分子筛进行了表征。结果表明,与传统的采用正硅酸乙酯为柱化剂的柱化过程相比,以四甲基铵硅酸盐为柱化剂时,已溶胀的前驱体不经干燥处理即可直接在含水体系进行柱化插层合成得到层间距均一的层柱状 MCM-36分子筛,适宜的合成条件为：先在80℃的高 pH 值(约13.5)环境下对前驱体溶胀24 h,然后在100℃下柱化插层24 h。表征结果表明,MCM-36分子筛具有层内微孔和层间介孔的复合孔道结构以及较大的比表面积(特别是外比表面积)；与 HMCM-22相比,HMCM-36的表面酸性虽明显降低,但其层间介孔结构的形成使大量 B酸中心暴露于大分子易于接近的层间介孔孔壁,可为涉及较大分子的催化反应提供更多可接近的活性位中心。
이층상 MCM-22P 위전구체,사갑기안규산염위주화제,채용동태수열법고찰료 MCM-36분자사적합성조건,병통과XRD、N2물리흡부、TEM、27 Al-MAS NMR 이급 NH3-TPD 등수단대합성분자사진행료표정。결과표명,여전통적채용정규산을지위주화제적주화과정상비,이사갑기안규산염위주화제시,이용창적전구체불경간조처리즉가직접재함수체계진행주화삽층합성득도층간거균일적층주상 MCM-36분자사,괄의적합성조건위：선재80℃적고 pH 치(약13.5)배경하대전구체용창24 h,연후재100℃하주화삽층24 h。표정결과표명,MCM-36분자사구유층내미공화층간개공적복합공도결구이급교대적비표면적(특별시외비표면적)；여 HMCM-22상비,HMCM-36적표면산성수명현강저,단기층간개공결구적형성사대량 B산중심폭로우대분자역우접근적층간개공공벽,가위섭급교대분자적최화반응제공경다가접근적활성위중심。
Pillared MCM-36 zeolites of MWW type were hydrothermally synthesized by pillaring swollenlayered MCM-22P precursor, with tetramethylammonium silicate as the pillaring reagent; the synthesized zeolites were characterized by different physico-chemical techniques such as XRD, N2 adsorption, TEM, 27 Al-MAS,NMR and NH 3-TPD. The results showed that the swollen MCM-22P without drying was successfully pillared in an aqueous solution system; the MCM-36 zeolites with an uniform interlayer distance were then readily obtained.The suitable synthesis conditions for MCM-36 are 80 ℃ for 24 h for the interlayer swelling of MCM-22P at high pH value (13.5), and then at 100 ℃ for 24 h for the formation of the intercalating pillars. The MCM-36 zeolites obtainedexhibit a typical MWW topology structure , with a composite pore system of both micropores in the crystalline layers and mesopores in the interlayer space, and a large specific surface area (especially external specific surface area).Compared with HMCM-22, the HMCM-36 zeolites show lower acid amount; however, a larger amount of structurally accessible Br?nsted acid sites located in the interlayer space of MCM-36 zeolites are exposed due to the formation ofmesopores in the interlayer space , which should be favorable to the reaction involving bulky molecules.