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- Title
Y 型分子筛中金属离子落位的调控及解析方法研究进展.
- Authors
赵晋川; 温志慧; 王静静; 常丽萍; 鲍卫仁; 马静红; 廖俊杰
- Abstract
Y-type zeolite is widely used in the field of desulfurization. Studies have shown that the removal capacity of sulfide in pollutants can be effectively improved by the metal-modified Y-type zeolite adsorbents obtained by metal ion exchange. However, due to the fact that the Y-type zeolite has three different size structures: super cage, sodalite cage and hexagonal prism cage, larger sulfides can only be adsorbed and removed by entering the super cage according to the size selectivity. Therefore, it is very important to improve its adsorption performance by analyzing and controlling the location of metal ions in Y-type zeolite. In this paper, the location control methods and analytical methods of metal ions in Y-type zeolite were summarized. The effects of the size of metal complexes, the calcination temperature and atmosphere during the preparation of zeolite, and the introduction methods of metal species on the position of metal ions in Y-type zeolite were summarized. The progress of characterization methods such as X-ray diffraction analysis(XRD), Rietveld structure refinement, in situ infrared spectroscopy(FTIR and Py-FTIR), and electron paramagnetic resonance(EPR) in analyzing the micro positioning of metals in Y-type zeolite cages was reviewed. The effective methods for characterizing the various metal species loaded on Y-type zeolite were analyzed. The size of metal complexes can be adjusted by complexing metal ions with organic complexes so that they can enter more into the super cages during the ion exchange process, achieving the purpose of regulating the location of metals in different cages of Y-type zeolite. The dehydration of hydrated metal ions caused by high temperature calcination is transferred from Y-type zeolite super cages to sodalite cages. The location of metal ions can be controlled by changing the calcination temperature. The calcination atmosphere will affect the valence state of the metal ions. The metal oxides obtained by calcination in the air atmosphere are prone to deposit and block the pores, hindering the migration of the metal ions. Some metal ions can be also reduced due to the calcination under nitrogen atmosphere and change the active components on the zeolite. The appropriate calcination temperature and atmosphere can affect the placement of metal ions in the Y-type zeolite cage. The introduction method of metal species will affect its distribution inside and outside the Y-type zeolite cage, and regulate its location in each cage of the Y-type zeolite. Y-type zeolite sieves have broad application prospects in the field of adsorption separation and catalysis, in which metal modification is a commonly used means to enhance the performance of Y-type zeolite sieves. In order to enhance the utilization rate of metal ions and increase the metal active sites, it is necessary to combine with suitable and analytical methods to clarify the migration law of metal ions in Y-type zeolite sieves under different preparation conditions. Further attention is focused on how to inhibit the migration of metal ions in the Y-type zeolite super cage under high temperature calcination, ensuring that more metal species are localized in the super cage. The mechanism by which the mode of introduction of metal species affects their colonization is unclear, and further research is needed. The methods for resolving the fall of metal ions in different cages of Y-type zeolite sieves are not intuitive, and some methods are controversial and need to be further explored and investigated.
- Subjects
LOCATION analysis; METAL ions; DESULFURIZATION; ZEOLITES
- Publication
Clean Coal Technology, 2023, Vol 29, Issue 11, p74
- ISSN
1006-6772
- Publication type
Article
- DOI
10.13226/j.issn.1006-6772.22102701