An INS study of entrapped organic cations within the micropores of zeolite RTH
| Autor: | Tetiana Lemishko, Fernando Rey, Jorge Simancas, Mónica Jiménez-Ruiz, German Sastre, Manuel Hernández-Rodríguez |
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| Rok vydání: | 2016 |
| Předmět: |
CALCINATION
DYNAMICS General Physics and Astronomy ZSM-18 02 engineering and technology Neutron scattering 010402 general chemistry 01 natural sciences Inelastic neutron scattering law.invention chemistry.chemical_compound symbols.namesake law PROGRAM Organic chemistry Calcination MOLECULAR-SYSTEMS SILICATES Physical and Theoretical Chemistry Zeolite Range (particle radiation) Microporous material 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry NEUTRON-SCATTERING SIMULATION symbols Physical chemistry INTERATOMIC POTENTIALS van der Waals force 0210 nano-technology Fluoride STRUCTURE-DIRECTING AGENTS |
| Zdroj: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia instname |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | [EN] Two different organic cations (structure directing agents, SDAs) have been selected because of their ability to drive the synthesis of zeolites towards the same microporous material, RUB-13 (RTH), both being organophosphorous compounds. These P containing structure directing agents are characterized by a high concentration of positive charge on the phosphorus atom. Then, in the presence of fluoride anions used in these syntheses, a strong P+ center dot center dot center dot F- electrostatic contribution competes with the van der Waals short range SDA . . . zeolite interaction that drives the zeolite formation. The rotation of the methyl groups present in the SDA is expected to be nearly free if van der Waals interactions dominate, but they will be hindered if the Coulombic P+ center dot center dot center dot F- term forces a closer approach to the SDA towards the zeolite framework. SDAs can be designed a priori to tune which interactions dominate. The rotational mobility of the SDAs, as well as certain related bending modes, has been well tackled by inelastic neutron scattering (INS) in order to test this hypothesis. The INS results provide valuable information for the design of specific SDAs for the synthesis of zeolites. Ministerio de Economia y Competitividad of Spain is thanked for the provision of funding through the excellence programme 'Sever Ochoa' (SEV-2012-0267) and MAT2015-71842-P. Generalitat Valenciana is acknowledged for funding through the PROMETEO program (PROMETEOII/2013/011). All authors thank ILL for neutron beam-time allocation (experiment 7-04-129) and ILL C-Lab for simulation support. GS thanks Centro Tecnico de Informatica (CTI-CSIC) for the use of computational facilities. GS and TL thank ILL for the provision of the contract SRH/GRI/AS-15/222 ("Inelastic Neutron Scattering study of zeolite acidity") and the PhD contract. Prof. Javier Campo is acknowledged for helpful suggestions. |
| Databáze: | OpenAIRE |
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