Origin of Nb₂ O₅ Lewis Acid Catalysis for Activation of Carboxylic Acids in the Presence of a Hard Base.

ABSTRACT: The Nb₂ O₅ surface catalyzes the amidation of carboxylic acids with amines through Nb⁵⁺ Lewis acid activation of the C=O group. In this work, DFT calculations were applied to theoretically investigate the C=O bond activation of a model carboxylic acid (acetic acid) on θ-Al₂ O₃ (110), anatase TiO₂ (101), and T-Nb₂ O₅ (100) surfaces. The adsorption sites, adsorption energies, reaction energy barriers, electronic properties, and vibrational frequency of acetic acid were examined in detail. It was found that the bond activation of the carbonyl group is most efficient on Nb₂ O₅ , although the adsorption energy is larger on Al₂ O₃ and TiO₂ . The most effi

SUBMITTER: Hirunsit P 

PROVIDER: S-EPMC6282532 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature