Journal article
Mechanochemical reaction pathways in solvent-free synthesis of ZSM-5
Microporous and mesoporous materials, Vol.276, pp.23-28
03/01/2019
DOI: 10.1016/j.micromeso.2018.09.009
Abstract
Solvent-free methods for the synthesis of ZSM-5 have been previously reported in the literature. These methods typically involve grinding the starting materials together prior to the hydrothermal reaction step. However, very little is known about the reaction intermediates formed during the mechanochemical pre-reaction or about how the pre-reaction impacts the subsequent hydrothermal synthesis conditions (temperature and length of hydrothermal treatment). In this study, the solvent-free synthesis of ZSM-5 was investigated while varying the length and type of grinding (manual, ball-mill) and the components of the reaction mixture. The initial reactions that occurred between the solid-state raw materials during grinding were monitored by powder X-ray diffraction (pXRD). Extended grinding initiates exchange reactions between several reagents to form NaCl and to liberate ammonia and water. The resulting wet paste undergoes facile thermal conversion to crystalline zeolite ZSM-5 framework structures. These results provide valuable insights used to guide the optimization of the synthesis conditions required to prepare stable, crystalline and high surface area ZSM-5 under solvent-free synthesis conditions. The solvent-free approach contributes to the overall goal of a greener, more sustainable ZSM-5 synthesis. [Display omitted] •Mechanochemical grinding pre-reactions monitored in solvent-free synthesis of ZSM-5.•Grinding initiates exchange reactions between starting materials.•The formation of NaCl and NH3 were observed during the grinding step.•A paste-like phase of the solid raw materials was formed after 15 min of grinding and leads to highly crystalline ZSM-5.•Insights on mechanochemistry useful for optimizing synthesis conditions.
Details
- Title: Subtitle
- Mechanochemical reaction pathways in solvent-free synthesis of ZSM-5
- Creators
- Majid H Nada - Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USAEdward G Gillan - Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USASarah C Larsen - Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA
- Resource Type
- Journal article
- Publication Details
- Microporous and mesoporous materials, Vol.276, pp.23-28
- Publisher
- Elsevier Inc
- DOI
- 10.1016/j.micromeso.2018.09.009
- ISSN
- 1387-1811
- eISSN
- 1873-3093
- Grant note
- DOI: 10.13039/100008893, name: University of Iowa; DOI: 10.13039/501100008982, name: NSF, award: CHE-1359063, CHE-1538847
- Language
- English
- Date published
- 03/01/2019
- Academic Unit
- Chemistry
- Record Identifier
- 9983985804802771
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