{"title":"Atomic and Electronic Structures on a Mordenite Zeolite","authors":"Shinya Hosokawa, Hitoshi Sato, Yasuhisa Tezuka, Jun-ichi Adachi, Koji Kimura, Koichi Hayashi, Shinji Kohara, Hiroo Tajiri, Kentaro Kobayashi, Akihide Koura, Fuyuki Shimojo","doi":"10.1380/ejssnt.2023-063","DOIUrl":null,"url":null,"abstract":"Atomic structures of an insulating and hydrophobic zeolite sample of mordenite were measured by high-energy X-ray diffraction, and a pair distribution function analysis was carried out. Valence- and conduction-band O 2p partial densities of states (DOSs) in a mordenite were measured by soft X-ray emission and absorption spectroscopies (SXES and SXAS), respectively. The SXAS spectrum for the conduction band O 2p orbital has characteristic structures like that of crystalline SiO2, while pre-shoulders are observed in mordenite. By choosing characteristic energies in the SXAS spectrum for the incident photon energies, SXES spectra were obtained, in which a large peak and three small peaks or shoulders can be assigned by a lone pair orbital and bonding (σ) ones, respectively. A density functional theory was applied to determine the exact atomic structures and electronic states, and they are in good agreement with the corresponding experiments. It is concluded that the O 2p partial DOS is mainly O-Si covalent bonds, and the Al and Na atoms have minor contributions for them. From this study, it was found that the fundamental properties of complex zeolites can only be obtained in combination of experimental and theoretical investigations as mentioned above, which can open feasibilities to uncover the origin of active sites in functional zeolites.","PeriodicalId":11626,"journal":{"name":"E-journal of Surface Science and Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.5000,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"E-journal of Surface Science and Nanotechnology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1380/ejssnt.2023-063","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"NANOSCIENCE & NANOTECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Atomic structures of an insulating and hydrophobic zeolite sample of mordenite were measured by high-energy X-ray diffraction, and a pair distribution function analysis was carried out. Valence- and conduction-band O 2p partial densities of states (DOSs) in a mordenite were measured by soft X-ray emission and absorption spectroscopies (SXES and SXAS), respectively. The SXAS spectrum for the conduction band O 2p orbital has characteristic structures like that of crystalline SiO2, while pre-shoulders are observed in mordenite. By choosing characteristic energies in the SXAS spectrum for the incident photon energies, SXES spectra were obtained, in which a large peak and three small peaks or shoulders can be assigned by a lone pair orbital and bonding (σ) ones, respectively. A density functional theory was applied to determine the exact atomic structures and electronic states, and they are in good agreement with the corresponding experiments. It is concluded that the O 2p partial DOS is mainly O-Si covalent bonds, and the Al and Na atoms have minor contributions for them. From this study, it was found that the fundamental properties of complex zeolites can only be obtained in combination of experimental and theoretical investigations as mentioned above, which can open feasibilities to uncover the origin of active sites in functional zeolites.
期刊介绍:
Our completely electronic and open-access journal aims at quick and versatile-style publication of research papers on fundamental theory and experiments at frontiers of science and technology relating to surfaces, interfaces, thin films, fine particles, nanowires, nanotubes, and other nanometer-scale structures, and their interdisciplinary areas such as crystal growth, vacuum technology, and so on. It covers their physics, chemistry, biology, materials science, and their applications to advanced technology for computations, communications, memory, catalysis, sensors, biological and medical purposes, energy and environmental problems, and so on.