Chem. Mater. 2010, 22, 3099–3107 3099 DOI:10.1021/cm100030x
Organotemplate-Free Syntheses of ZSM-34 Zeolite and Its Heteroatom-Substituted Analogues with Good Catalytic Performance Lin Zhang,‡ Chengguang Yang,‡ Xiangju Meng,† Bin Xie,‡ Liang Wang,‡ Limin Ren,‡ Shujie Ma,‡ and Feng-Shou Xiao*,† †
Key Laboratory of Applied Chemistry and Department of Chemistry (Xixi Campus), Zhejiang University, Hangzhou 310028, China, and ‡State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023, People’s Republic of China Received January 4, 2010. Revised Manuscript Received April 5, 2010
The organotemplate-free route for syntheses of aluminosilicate ZSM-34 zeolite and its heteroatom-substituted analogues (B, Ga, and Fe) in the presence of zeolite L seeds solution has been extensively investigated. Many factors such as the amount of zeolite L seeds solution, SiO2/Na2O ratio in the starting aluminosilicate gel, crystallization temperature, and time influence the crystallization of ZSM-34 zeolite significantly. The pure phase of ZSM-34 zeolite could only be obtained in a narrow phase diagram of Na2O-Al2O3-SiO2-H2O by a comprehensive consideration of these factors. Heteroatoms such as B, Ga, and Fe substituted ZSM-34 zeolites can also be synthesized by this organotemplate-free route. Catalytic tests in the conversion of methanol to olefins (MTO) at the temperature of 400 °C and weight hourly space velocity (WHSV) of 0.5 h-1 over aluminosilicate ZSM-34 and its analogues containing framework B and Ga show that these ZSM-34 catalysts exhibit higher selectivities for ethylene and propylene (>80%) than ZSM-5 zeolite (
