Oshimura Haruna, Tanaka Shuuma, Nagata Shouya, Matsuura Shinya, Hashimoto Tadanori, Ishihara Atsushi
Mie University, 1577 Kurima Machiya-Cho, Tsu City, Mie Prefecture, 514-8507, Japan.
Mie Prefectural Industrial Research Institute, 5-5-45 Takajyaya, Tsu City, Mie Prefecture, 514-0819, Japan.
Chempluschem. 2024 Dec;89(12):e202400447. doi: 10.1002/cplu.202400447. Epub 2024 Oct 29.
The gel skeletal reinforcement (GSR) method was applied at the preparation stage of β-zeolite to prepare a novel hierarchical catalyst. A solution of hexamethyldisiloxane (HMDS) and acetic anhydride, a GSR reagent, was added to the mixture of colloidal silica, sodium aluminate, tetraethylammonium hydroxide, sodium hydroxide and water, and successive aging and hydrothermal treatment gave microporous β-zeolite surrounded by mesoporous silica like core-shell structure. Its properties were characterized by XRD, nitrogen adsorption and desorption, NH-TPD, TEM, and TG-DTA measurements, and further characteristics of the catalysts produced were clarified by the catalytic cracking of n-dodecane. The hierarchical structure of microporous zeolite and mesoporous silica was shown from GSR-2.9HS-H-Beta to GSR-3.2HS-H-Beta, where the molar ratio of HMDS and silica source of β-zeolite was 2.9~3.2 : 100. It was found that in the catalytic cracking of n-dodecane, the relative activity (the conversion per the amount of zeolite crystals) increased with the increase in mesopore volume and surface area. The result indicated that the introduction of mesopores was effective even in catalytic cracking of small molecule of n-dodecane.
在β沸石的制备阶段采用凝胶骨架增强（GSR）法制备了一种新型分级催化剂。将六甲基二硅氧烷（HMDS）和乙酸酐的溶液（一种GSR试剂）加入到胶体二氧化硅、铝酸钠、氢氧化四乙铵、氢氧化钠和水的混合物中，经过连续老化和水热处理得到了具有核壳结构的微孔β沸石，其周围包裹着介孔二氧化硅。通过XRD、氮气吸附-脱附、NH-TPD、TEM和TG-DTA测量对其性能进行了表征，并通过正十二烷的催化裂化进一步阐明了所制备催化剂的特性。从GSR-2.9HS-H-Beta到GSR-3.2HS-H-Beta显示出微孔沸石和介孔二氧化硅的分级结构，其中HMDS与β沸石硅源的摩尔比为2.9~3.2∶100。研究发现，在正十二烷的催化裂化中，相对活性（每单位沸石晶体量的转化率）随着介孔体积和表面积的增加而提高。结果表明，即使在小分子正十二烷的催化裂化中，介孔的引入也是有效的。
