Enhanced recovery and recycling of catalyst by post-impregnation of γ-Al2 O3 with 12-tungstophosphoric acid for esterification reaction
| Autor: | Pegah Nazari, Shahrbanoo Rahman Setayesh |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Chemistry
General Chemical Engineering Kinetics Inorganic chemistry Alcohol 02 engineering and technology Activation energy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Catalysis Keggin structure chemistry.chemical_compound Reaction rate constant Polyoxometalate Leaching (metallurgy) 0210 nano-technology |
| Zdroj: | The Canadian Journal of Chemical Engineering. 96:1176-1184 |
| ISSN: | 0008-4034 |
| Popis: | 12-tungstophosphoric acid, polyoxometalate with Keggin structure, and γ-Al2O3 were synthesized. Loading of 12-tungstophosphoric acid (HPW) on γ-Al2O3 was performed by post-impregnation method. The catalysts were characterized by XRD, SEM, FTIR, BET, and DRS techniques. According to the pertinent observation, using post-impregnation method promises the stability of polyoxometalate Keggin structure after loading on γ-Al2O3 support. The stability of 20 %HPW/Al2O3 was also confirmed by leaching test. Textural characterization demonstrates that HPW on the γ-Al2O3 had much larger surface area as compared with the pure HPW. The 20 %HPW/Al2O3 exhibited roughly high activity toward esterification reaction. The influence of various reaction parameters (% loading HPW on support, reaction temperature, reaction time, catalyst weight, and acid/alcohol molar ratio) on the catalytic performance was studied. The efficiency of catalytic activity for six cycles approximately remains constant, which confirms the enhanced recovery and recycling of catalyst. The kinetics of esterification reaction and kinetic parameters such as rate constants and activation energy were determined (25.37 kJ/mol). This article is protected by copyright. All rights reserved |
| Databáze: | OpenAIRE |
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