State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology
Key Laboratoryof Coal Science and Technology of Ministry of Education,Taiyuan University of Technology
Shanxi ZhejiangUniversity New Materials and Chemical Research Institute
College of Chemistry and Chemical Engineering,Taiyuan University of Technology

Y型分子筛在脱硫领域有广泛应用。研究表明,经过金属离子交换得到的金属改性Y型分子筛吸附剂可较好改善污染物中硫化物的脱除能力,但由于Y型分子筛具有超笼、方钠石笼和六棱柱笼3个不同尺寸的结构,根据尺寸选择性,较大的硫化物只能进入超笼中吸附脱除,所以解析和调控金属离子在Y型分子筛中的落位对提升其吸附性能十分重要。总结了Y型分子筛中金属离子的落位调控方法和解析手段,归纳了金属配合物的尺寸、分子筛制备过程中的焙烧温度和气氛以及金属物种引入方式等对金属离子在Y型分子筛中位置的影响行为。综述X射线衍射分析(XRD)、Rietveld结构精修、原位红外光谱(FTIR和Py-FTIR)、电子顺磁共振(EPR)等表征手段在解析金属在Y型分子筛笼内的微观定位方面取得的进展,分析了负载于Y型分子筛上形式多变的金属物种有效的表征手段。通过金属离子和有机配合物的络合,调节金属配合物尺寸,使其在离子交换过程中更多地进入超笼中,可达到调控金属落位在Y型分子筛不同笼中的目的;高温焙烧引起水合金属离子脱水使其从Y型分子筛超笼转移到方钠石笼中,改变焙烧温度可调控金属离子的落位。焙烧气氛会影响金属离子的价态,空气气氛下焙烧得到的金属氧化物易发生沉积而堵塞孔道,妨碍金属离子的迁移;而氮气气氛下焙烧还会使部分金属离子还原,改变分子筛上的活性组分,合适的焙烧温度和气氛可影响金属离子在Y型分子筛笼中的落位。金属物种的引入方式会影响其在Y型分子筛笼内外的分布,调控其在Y型分子筛各笼中的落位。Y型分子筛在吸附分离和催化领域应用前景广阔,其中金属改性是常用的提升Y型分子筛性能的手段。为提升金属离子利用率,增加金属活性位点,必须结合合适的解析方法,明确不同制备条件下金属离子在Y型分子筛中的迁移规律。指出如何抑制Y型分子筛超笼中金属离子在高温焙烧下的迁移,保证更多金属物种定位在超笼中是进一步关注的重点;金属物种引入方式对其落位的影响机制尚不明确,需进一步研究;金属离子在Y型分子筛不同笼中落位解析方法不直观、部分方法存在争议,需进一步探索研究。

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 thefact that the Y-type zeolite has three different size structures: supercage, sodalite cage and hexagonal prism cage, larger sulfides can onlybe adsorbed and removed by entering the supercage according to the size selectivity. Therefore, it is very important to improve its adsorption performance by analyzing and controling the location of metal ions in Y-type zeolite. In this paper, the location control methods andanalytical methods of metal ions in Y-type zeolite were summarized. The effects of the size of metal complexes, the calcination temperatureand 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 positioningof metals in Y-type zeolite cages was reviewed. The effective methods for characterizing the various metal species loaded on Y-type zeolitewere analyzed. The size of metal complexes can be adjusted by complexing metal ions with organic complexes so that they can enter moreinto the supercages during the ion exchange process, achieving the purpose of regulating the location of metals in different cages of Y-typezeolite. The dehydration of hydrated metal ions caused by high temperature calcination is transfered from Y-type zeolite supercages to sodalite cages. The location of metal ions can be controled by changing the calcination temperature. The calcination atmosphere will affect thevalence 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 atmosphereand change the active components on the zeolite. The appropriate calcination temperature and atmosphere can affect the placement of metalions in the Y - type zeolite cage. The introduction method of metal species will affect its distribution inside and outside the Y - typezeolite cage, and regulate its location in each cage of the Y-type zeolite. Y-type zeolite sieves have broad application prospects in the fieldof 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 suitableand 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 supercage under high temperature calcination, ensuring that more metal species are localized in the supercage. The mechanism by which the mode of introduction of metal species affectstheir colonization is unclear, and further research is needed. The methods for resolving the fall of metal ions in different cages of Y-typezeolite sieves are not intuitive, and some methods are controversial and need to be further explored and investigated.

国家自然科学基金面上资助项目(22078222);山西浙大新材料与化工研究院技术开发资助项目(2022SX-TD014)

赵晋川,温志慧,王静静,等.Y 型分子筛中金属离子落位的调控及解析方法研究进展[J].洁净煤技术,2023,29(11):74-82.

ZHAO Jinchuan,WEN Zhihui,WANG Jingjing,et al.Research progress on regulation and analytical methods of metal ionlocation in Y-type zeolite[J].Clean Coal Technology,2023,29(11):74-82.