Confinement Effects in Protonation Reactions Catalyzed by Zeolites with Large Void Structures

ZALAZAR, MARÍA FERNANDA; CABRAL, NÉSTOR DAMIÁN; ROMERO OJEDA, GONZALO DAVID; ALEGRE, CLARA IRIS AYMARÁ; PERUCHENA, NELIDA MARIA

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Año: 2018 vol. 122 p. 27350 - 27359

1932-7447

In the present work, we studied the protonation reaction of styrene inside the cavity of acidic H-Y zeolite. Density functional theory calcu kglation using M06-2X functional and quantum theory of atoms in molecules analysis are used in order to investigate the confinement effects of zeolite framework on species involved on the reaction. A detailed analysis of the topology of the electron density of interactions among reactants, TS and intermediate products with the cavity of H-Y zeolite is performed, extracting conclusions about adsorption, catalysis and confinement effects. Identification and quantification of host-guest interactions between zeolite framework and styryl cation support the larger contribution of weak closed-shell interactions in stabilization of the formed carbenium ion. Our results clearly show that reaction energies for all formed species inside a zeolite with large void structure are also significantly governed by the confinement effects related to weak host-guest interactions. In other words, zeolite confinement effect is crucial factor that may affect the catalytic activity even on zeolites with large pore size and void structure as H-Y.