Theoretical study of the adsorption of acetic acid and methanol on H-BETA zeolite

GLAUCIO GOMES; LINDINO, C. A; ZALAZAR, M. F.; PERUCHENA, N. M.

Aguas de Lindoia

Congreso; 38ª Reunião Anual da Sociedade Brasileira de Química.; 2015

Sociedade Brasileira de Química.

The mechanism of the esterification of organic acids with alcohols catalyzed by acidic zeolites has many assumptions, with different models of adsorption of organic species being of great interest to the compression of the behavior of the solid acid catalyst in this process. In this work we studied the adsorption of acetic acid/methanol following the mechanisms proposed by Kirumakki et al., 2006 and Bedard et al., 2012. Different models of adsorption of acetic acid and methanol on the surface of H-BETA zeolite have been studied in order to provide information that could be helpful in the interpretation of the first step of the mechanism. The zeolite catalyst has been modeled by an extended cluster model 52T for H-BETA, with an overall composition H63 O73 Si51 Al. In this work, the adsorption of acetic acid and methanol in H-BETA has been systematically studied using ONIOM (M06-2X/6-31G (D):PM6) and M06-2X/6-31G (D) methods and the Gaussian 09 program. In the ONIOM scheme, the zeolite was represented by a 3T/52T model for the high and low layer, respectively. The high layer also includes the adsorbed molecules