This study aims at comparing both thermal stability and adsorption properties of a Hierarchically Organized ZSM-5 zeolite (MFI topology, silica/alumino=25) toward two amino acids chosen as model: L-lysine and cysteine as single and binary mixtures. Lysine (Lys) is chosen because of its unique structure, where there is one single sidechain amine group; cysteine (Cys) is an accessible biomolecule with a thiol group which may be very active in the catalysis. Hierarchical ZSM-5 is selected as adsorbent because of its high surface area and 3D pore structure containing two intersecting 1D channels both delimited by 10-membered rings (5.4 x 5.6 Å and 5.1 x 5.5 Å window sizes, respectively). Due to their molecular dimensions, both Lys and Cys amino acids can access the zeolites micro and mesoporous, thus originating unique catalytic functionalities. The adducts of zeolite and binary mixture of the selected amino acids will be investigated for the first time by a structural approach in order to get a deep understanding of the host guest interactions of organics and zeolite as well as provide insight into the zeolite selectivity in the their adsorption/desorption processes. However no in situ structural investigation of Hierarchically Organized ZSM-5 dynamics as a function of the amino acids adsorption/desorption processes has been ever performed on this adsorbent. These information are crucial in order to utilize HOZs-ZSM-5 active sites more efficiently in catalytic applications as well as improve the transport attributes, in terms of the catalyst effectiveness. In order to fulfill these objectives, we submit this proposal for beamtime access at the MCX beamline of the Elettra synchrotron source, as it provides the possibility to obtain high-resolution data, suitable for crystal structure refinements, at high temperatures using a hot air blower.
Structural characterization and thermal stability of hierarchically organized ZSM-5 zeolite loaded with amino-acids: evidences of competive adsorption by in situ Synchrotron X-ray powder diffraction
annalisa martucci
Primo
2019
Abstract
This study aims at comparing both thermal stability and adsorption properties of a Hierarchically Organized ZSM-5 zeolite (MFI topology, silica/alumino=25) toward two amino acids chosen as model: L-lysine and cysteine as single and binary mixtures. Lysine (Lys) is chosen because of its unique structure, where there is one single sidechain amine group; cysteine (Cys) is an accessible biomolecule with a thiol group which may be very active in the catalysis. Hierarchical ZSM-5 is selected as adsorbent because of its high surface area and 3D pore structure containing two intersecting 1D channels both delimited by 10-membered rings (5.4 x 5.6 Å and 5.1 x 5.5 Å window sizes, respectively). Due to their molecular dimensions, both Lys and Cys amino acids can access the zeolites micro and mesoporous, thus originating unique catalytic functionalities. The adducts of zeolite and binary mixture of the selected amino acids will be investigated for the first time by a structural approach in order to get a deep understanding of the host guest interactions of organics and zeolite as well as provide insight into the zeolite selectivity in the their adsorption/desorption processes. However no in situ structural investigation of Hierarchically Organized ZSM-5 dynamics as a function of the amino acids adsorption/desorption processes has been ever performed on this adsorbent. These information are crucial in order to utilize HOZs-ZSM-5 active sites more efficiently in catalytic applications as well as improve the transport attributes, in terms of the catalyst effectiveness. In order to fulfill these objectives, we submit this proposal for beamtime access at the MCX beamline of the Elettra synchrotron source, as it provides the possibility to obtain high-resolution data, suitable for crystal structure refinements, at high temperatures using a hot air blower.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
