Estudio comparativo de la adsorción de ácido levulínico y metanol en zeolitas ácidas de diferente topología: efecto de la estructura sobre la actividad catalítica

ROMERO OJEDA, GONZALO D.; ESQUENAZI, E. N.; PERUCHENA, N. M.; ZALAZAR, M. F.

NATAL

Congreso; XXVIII CONGRESSO IBERO-AMERICANO DE CATÁLISE; 2022

IBERO AMERICANA DE CATALISIS

Among several bio-based chemical synthesis routes, the esterification of levulinic acid to levulinate esters using solid acid catalyst such as acid zeolites provide an alternative route with more environmentally friendly chemical processes. Previous experimental work founds that the activity of the zeolites seems to be related more to their structure than to their total acid activity. The aim of this work was to study the adsorption of levulinic acid and methanol as the first step in the reaction mechanism of levulinic acid esterification by methanol in acid zeolites of different topologies and to determine how the structure of these catalysts influences the adsorption energy and the catalytic activity. The optimizations were carried out using the ONIOM scheme at the M06-2X/6-31G (d):PM6 level. The zeolite catalyst structure has been modeled by a 14T/46T cluster model for H-ZSM-5, 17T/52T for H-Beta , 18/84T for H-Y and 16T/112T for H-MOR. Our results show that the structure of the catalyst influences the adsorption mode of both reagents and therefore the stability of the complexes formed. In three-dimensional zeolites such as H-Beta, the size of the cavity allows the formation of more stable coadsorbed complexes and would be associated with its more favorable catalytic activity.