Simplistic transesterification approach for the synthesis of benzyl salicylate over honeycomb monoliths coated with modified forms of zirconia as catalysts: Kinetics.

Autor: Pratap, S. R., Shamshuddin, S. Z. M., Thimmaraju, N., Mohan Kumar, T. E.
Předmět:
Zdroj: Chemical Engineering Communications; 2018, Vol. 205 Issue 4, p557-570, 14p, 1 Color Photograph, 2 Black and White Photographs, 3 Diagrams, 2 Charts, 9 Graphs
Abstrakt: The catalysts such as Al2O3/ZrO2 with 2–10 wt% of Al2O3 were coated on honeycomb monoliths by dip-and-dry technique. These catalysts were also prepared in their powder form. All the catalysts (honeycomb and powder form) were characterized for their surface acidity, crystallinity, functionality, elemental analysis, and morphology. The catalytic activity of all the catalysts was performed in the transesterification of methyl salicylate with benzyl alcohol to synthesize benzyl salicylate. Reaction conditions like reaction time, reaction temperature, and the molar ratio of the reactants were varied to obtain the highest yield of benzyl salicylate. The 6% Al2O3/ZrO2 coated on honeycomb exhibited the highest conversion of methyl salicylate at 383 K in 60 min. Kinetic studies were conducted to determine the energy of activation and temperature coefficient. The rate constants in the case of 6AZ (HCM) was found to be 5.0 × 10−3 min−1 (373 K); 6.4 × 10−3 min−1 (383 K) and 2.2 × 10−3 min−1 (373 K); 3.2 × 10−3 min−1 (383 K) in the case of 6AZ (PF) catalyst, while the energy of activation (Ea) values were found to be 35.12 and 39.93 kJ mol−1 for 6AZ (HCM) and 6AZ (PF), respectively. The reactant preadsorption study discloses that the transesterification follows the Eley–Rideal mechanism. Reactivation and recyclability of the catalysts were also examined and the results clearly indicate that Al2O3/ZrO2 coated on the honeycomb is efficient and green catalytic system. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje