Abstract

MESA, Santiago; ARBOLEDA, Johana  and  ECHAVARRIA, Adriana. Synthesis and modification of beta zeolite for use in toluene disproportionation reaction. Dyna rev.fac.nac.minas [online]. 2016, vol.83, n.196, pp.184-193. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v83n196.51933.

In this paper zeolite Beta was synthesized and characterized by XRD, ATG, ATD, XRF and SEM. Subsequently various modifications were made using a surface passivation process in liquid phase with tetraethylorthosilicate (TEOS), using two loads of TEOS and three passivation cycles, in order to obtain six catalysts. These materials were characterized by NH3-TPD and tested in tolune disproportionation reaction, under different conditions of pressure and temperature. As modification cycles were increased for each catalyst, there was a change in the acidity of the solids, mainly due to deposition of an inert layer of silica on the external surface. These results were confirmed with the improvement in para-selectivity and decreasing in conversion. Despite zeolite Beta is a large pore zeolite, an improvement of the para-selectivity was obtained, achieving almost stable values for the entire range of temperature and pressure conditions.

Keywords : Beta zeolita; Surface Passivation; Catalysis; Toluene Disproportionation; Para-selectivity.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )