The effect of mesoporosity in the reaction of vinyl acetate and isoamyl alcohol catalyzed by H-ZSM-5 zeolites based on natural Perlite

Abstract

Diverse ZSM-5 zeolites having a dual porosity and different acidic properties have been prepared using natural Perlite as source of SiO2 and Al2O3. Two traditional methodologies were selected to generate hierarchical porosity in the parent ZSM-5: (1) soft templating approach to produce an ordered micro-mesoporous material (H-ZSM-5/MCM-41) and (2) different duration of alkaline treatment for the generation of intra-crystalline mesoporosity (H-ZSM-5-MS-x, x = 30, 60 and 90). Surface acidity and accessibility indexes were determined by adsorption of pyridine and 2,6-lutidine. The catalytic activity was evaluated in the reaction of vinyl acetate and isoamyl alcohol which produces isoamyl acetate and acetaldehyde diisoamyl acetal by transesterification and ketalization reactions, respectively. Isoamyl acetate has been selectively produced as a consequence of an adequate combination of Brønsted acidity and accessibility, thus H-ZSM-5/MCM-41 and H-ZSM-5-MS-60 presented enhanced catalytic activity and selectivity compared to the parent H-ZSM-5.