Synthesis of highly crystalline nanosized HZSM-5 catalyst employing combined hydrothermal and sonochemical method: Investigation of ultrasonic parameters on physico-chemical and catalytic performance in methanol to propylene reaction
| Autor: | Fereydoon Yaripour, Jafar Towfighi Darian, Seyyed Mohammad Mousavi, Fatemeh Gorzin |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Sonication 02 engineering and technology 010402 general chemistry 01 natural sciences Autoclave Catalysis law.invention Inorganic Chemistry chemistry.chemical_compound Crystallinity law Materials Chemistry Physical and Theoretical Chemistry Crystallization 021001 nanoscience & nanotechnology Condensed Matter Physics Nanomaterial-based catalyst 0104 chemical sciences Electronic Optical and Magnetic Materials chemistry Chemical engineering Ceramics and Composites Methanol Particle size 0210 nano-technology |
| Zdroj: | Journal of Solid State Chemistry. 271:8-22 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2018.12.016 |
| Popis: | Nanostructured HZSM-5 catalysts were synthesized using sonochemical and hydrothermal techniques. The central composite experimental design method was applied to investigate the effects of three critical preparation variables including ultrasound power, irradiation time, and sonication temperature on the structure of the prepared catalysts. The catalysts were characterized by XRD and FE-SEM techniques. The catalytic performance of the selected catalysts was also evaluated in methanol conversion to propylene reaction. The results showed that higher crystallinity and lower particle size were obtained by increasing the above-mentioned factors. The maximum relative crystallinity and minimum mean particle size were obtained as 55.5% and 62.4 nm, respectively, under the optimal conditions of ultrasound power (231 W), irradiation time (21.2 min), and sonication temperature (42.7 °C). The mean particle size of the parent and sonicated HZSM-5 nanocatalysts which were prepared using 48 and 4 h crystallization in autoclave, were 893 and 62.4 nm, respectively. The optimum sonicated catalyst showed higher selectivities to propylene (C3=, 36.8%) and lower selectivity to total heavy hydrocarbons (C5+, 16.1%) compared to the parent catalyst. These results strongly suggest that a nanocatalyst with smaller particle size and higher crystallinity can be obtained in a lower crystallization time using ultrasound method which shows better performance in methanol to propylene reaction. |
| Databáze: | OpenAIRE |
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