Study of Confinement and Catalysis Effects of the Reaction of Methylation of Benzene by Methanol in H-Beta and H-ZSM-5 Zeolites by Topological Analysis of Electron Density
| Autor: | Nelida Maria Peruchena, Gonzalo David Romero Ojeda, María Fernanda Zalazar, Esteban Nadal Paredes, Néstor Damián Cabral |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
QUANTUM THEORY OF ATOMS IN MOLECULES
Físico-Química Ciencia de los Polímeros Electroquímica 02 engineering and technology 010402 general chemistry Photochemistry Heterogeneous catalysis 01 natural sciences DFT Catalysis purl.org/becyt/ford/1 [https] chemistry.chemical_compound Adsorption purl.org/becyt/ford/1.4 [https] Physical and Theoretical Chemistry Zeolite Benzene CARBENIUM IONS HOST-GUEST INTERACTIONS Otras Ciencias Químicas Atoms in molecules Ciencias Químicas 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy Química Orgánica chemistry HETEROGENEOUS CATALYSIS Density functional theory ZSM-5 0210 nano-technology CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| DOI: | 10.1021/acs.jpcc.7b10297 |
| Popis: | In this work we studied the host-guest interactions between confined molecules and zeolites and their relationship with the energies involved in the reaction of methylation of benzene by methanol in H-ZSM-5 and H-Beta zeolites employing density functional theory (DFT) methods and the quantum theory of atoms in molecules. Results show that the strength of the interactions related to adsorption and coadsorption processes is higher in the catalyst with the larger cavity; however, the confinement effects are higher in the smaller zeolite, explaining, from an electronic viewpoint, the reason why the stabilization energy is higher in H-ZSM-5 than in H-Beta. The confinement effects of the catalyst on the confined species for methanol adsorption, benzene coadsorption, and the formed intermediates dominate this stabilization. For the transition state (TS), the stability of the TS is achieved due to the stabilizing effect of the surrounding zeolite framework on the formed carbocationic species (CH3+) which is higher in H-ZSM-5 than in H-Beta. In both TSs the methyl cation is multicoordinated forming the following H2O···CH3+···CB concerted bonds. It is demonstrated that, through the electron density analysis, the criteria can be defined to discriminate between interactions related to the confinement effects and the reaction itself (adsorption, coadsorption, and bond-breaking and bond-forming processes) and, thus, to discriminate the relative contributions of the degree of confinement to the reaction energies for two zeolite catalysts with different topologies. Fil: Zalazar, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina Fil: Paredes, Esteban Nadal. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina Fil: Romero, Gonzalo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina Fil: Cabral, Néstor Damián. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina Fil: Peruchena, Nelida Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina |
| Databáze: | OpenAIRE |
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