Organotemplate-free, seed-directed, and rapid synthesis of Al-rich zeolite MTT with improved catalytic performance in isomerization of m-xylene

• Published in: Microporous and mesoporous materials 2014-03, Vol.186, p.106-112
• Main Authors: Wu, Qinming, Wang, Xiong, Meng, Xiangju, Yang, Chengguang, Liu, Yan, Jin, Yinying, Yang, Qi, Xiao, Feng-Shou
• Format: Article
• Language: English
• Subjects: Al-rich ZSM-23; Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Improved catalytic performance; Ion-exchange; Isomerization of m-xylene; Porous materials; Rapid synthesis; Seed-directed; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolites: preparations and properties
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2013.11.043

An organotemplate-free, seed-directed, and rapid synthesis of Al-rich MTT zeolite designated as ZJM-6 has been demonstrated. Catalytic tests in m-xylene isomerization show that H-form of ZJM-6 exhibits much higher activity than conventional ZSM-23 zeolite synthesized in the presence of organic template. [Display omitted] •MTT zeolite has been synthesized via the seed-directed and organotemplate-free route.•Seed-directed and organotemplate-free synthesis has very fast crystallization rate.•The Al-rich MTT zeolites contain stable aluminum species in the framework.•The Al-rich MTT zeolites show superior catalytic activity in m-xylene isomerization. m-xylene isomerization over zeolites is of great importance because of the shortage of p-xylene currently. Here, we show an organotemplate-free, seed-directed, and rapid synthesis of Al-rich zeolite MTT (denoted as ZJM-6) with improved catalytic performance in isomerization of m-xylene to p-xylene. Physicochemical characterizations including XRD, SEM, Ar sorption isotherms, 27Al NMR, and NH3-TPD show that the zeolitic product has good crystallinity, uniform crystals, high surface area, tetrahedral Al3+ species, and abundant acidic sites. Interestingly, the crystallization of ZJM-6 takes very short time (5h at 170°C), compared with conventional MTT zeolites (20h at 170°C). Very importantly, catalytic tests for m-xylene isomerization show that H-form of ZJM-6 zeolite exhibits superior performance, which could be potentially important for industrial applications of ZJM-6 zeolite as a candidate in the future.