Abstract:In this work, the interactions of aroma substances including benzyl alcohol, damascenone, ethyl vanillin and ethyl acetate with the surfaces of MCM-41 zeolite were investigated. Temperature programmed desorption (TPD) experiments were conducted separately to determine the TPD curves of these four kinds of aroma molecules on the MCM-41, and then estimate their desorption activation energies. Their electronegativity was calculated using abinitio calculation. Results showed that desorption activation energies of benzyl alcohol, damascenone, ethyl vanillin and ethyl acetate on the MCM-41 separately were 86.16, 71.13, 55.47 and 46.09 kJ/mol, respectively. The electronegativity of benzyl alcohol, damascenone, ethyl vanillin and ethyl acetate were 2.386, 2.664, 3.064 and 3.521, respectively. According to the HSAB theory, benzyl alcohol and damascenone belonged to the software base substances, and ethyl vanillin and ethyl acetate were the hard base substances. The interactions of benzyl alcohol and damascenone with the MCM-41 were much stronger than those of ethyl vanillin and ethyl acetate with the MCM-41, suggesting that the surfaces of the MCM-41 had the nature of soft acid substance.
