An unusual hierarchical ZSM-5 microsphere with good catalytic performance in methane dehydroaromatization

• Published in: Microporous and mesoporous materials Vol. 118; no. 1; pp. 169 - 175
• Main Authors: Chu, Naibo, Yang, Jianhua, Li, Chunyan, Cui, Jiaoying, Zhao, Qingyu, Yin, Xiaoyan, Lu, Jinming, Wang, Jinqu
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.02.2009; Elsevier
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Ion-exchange; Mesopores; Methane dehydroaromatization; Microsphere; Mo/HZSM-5-MS; Porous materials; Self-assembly; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolites: preparations and properties; Mo/HZSM-5-MS; Self-assembly; Methane dehydroaromatization; Microsphere; Mesopores; Methane; Self assembly; Binary compound; Shape; Micropore; Growth; Adsorption isotherm; Porous material; Silica; Structure; Scanning electron microscopy; Catalytic reaction; Crystals; Crystallization; X ray diffraction; Mesoporosity; Heterogeneous catalysis; Microporosity; Transmission electron microscopy; Models; Catalyst
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2008.08.048

In this paper, a novel hierarchical ZSM-5 microsphere (simplified as ZSM-5-MS hereafter) of about 3 μm, which is assembled by many French fries-like crystals (in shape of French fries) of about 100 nm in width, was synthesized by using SBA-15 as the silica source. ZSM-5-MS exhibited a unique geometrical shape which was entirely distinct from the conventional MFI shape. The N 2 adsorption isotherm suggested that the ZSM-5-MS had a uniform mesopores of 15 nm with a tail up to 45 nm. The ZSM-5-MS was modified to form a Mo/HZSM-5-MS catalyst which exhibited good catalytic performance in methane dehydroaromatization (MDA) due to the presence of both micropores and mesopores. A time trial study was carried out by SEM, XRD and TEM analysis for the insight into the growth of the obtained ZSM-5-MS. A growth model via self-assembly combined with crystallization process was proposed based on the time trial observations. The demonstrated route may be extended to synthesize other types of zeolites with unusual structure and properties.