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DFT investigations for "Fischer" esterification mechanism over silica-propyl-SO3H catalyst: Is the reaction reversible?
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DFT investigations for "Fischer" esterification mechanism over silica-propyl-SO3H catalyst: Is the reaction reversible?

Vafaeezadeh, M

DFT investigations for "Fischer" esterification mechanism over silica-propyl-SO3H catalyst: Is the reaction reversible?

Vafaeezadeh, M ; Sharif University of Technology | 2015

312 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.comptc.2015.07.028
  3. Publisher: Elsevier , 2015
  4. Abstract:
  5. For the first time, the mechanism of Fischer esterification between acetic acid and ethanol over silica-functionalized propylsulfonic acid (silica-propyl-SO3H) catalyst was explored by means of computational modeling techniques. For this purpose, 6-edge-atom cage-like cluster comprising Si-O-Si sequences has been selected to represent the surface of the catalyst. The results indicate that the reaction goes through concerted transition states. In all optimized structures no proton (H+) transfer occurs from catalyst to the substrates and the role of the catalyst is via the activation of the substrates through the formation of strong hydrogen bonds (H-bonds). Furthermore, the energetic diagram demonstrates that the activation energies of forward (esterification) and reverse (ester hydrolysis) reactions only differ by 0.3kcal/mol. The quantum theory of atoms in molecules (QTAIM) analysis was performed to investigate the nature of H-bonds. Another mechanism in which the catalyst has been acted as the Brønsted acid/base was also provided for this reaction
  6. Keywords:
  7. Acid catalyst ; DFT ; Fischer esterification ; Mechanism ; Modeling
  8. Source: Computational and Theoretical Chemistry ; Volume 1071 , 2015 , Pages 27-32 ; 2210271X (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S2210271X15003151