煤矸石微波辅助合成沸石分子筛的研究

为探究煤矸石合成沸石分子筛的最优工艺,以煤矸石为主要原料,采用传统水浴加热与微波辅助加热的方法,合成4A型沸石分子筛与P型沸石分子筛,利用电子显微镜和X射线衍射,对其形貌和结构进行分析表征。实验通过制备相同的沸石分子筛,得出制备沸石分子筛的煤矸石需要高岭石含量较高、有害杂质含量较低及较为合适的粒径(3μm～50μm)。相较于传统水浴加热,微波辅助加热得到的沸石分子筛纯度低,但加热时间仅需30 min～40 min,而传统水浴加热合成需要24 h,同时微波辅助加热还提高了沸石分子筛反应速率和分散度。     

MFI型沸石分子筛膜的研究进展及应用

综述了MFI型沸石分子筛膜制备方法的研究进展,突出介绍了较为成熟的水热合成法、微波合成法以及气相转移法,讨论了MFI型沸石分子筛膜在应用方面具有优势的有机物提纯、气体分离以及催化反应的研究进展,并提出了MFI型沸石分子筛膜制备和应用方面一些亟待解决的问题。     

微波技术在沸石分子筛材料合成中的应用研究进展

综述微波技术在多种常规沸石分子筛、纳米沸石分子筛以及分子筛膜合成过程中的研究进展。微波较常规水热合成能够大大缩短反应时间,有利于生成晶粒尺寸更小的晶体。对国内外开展微波合成沸石分子筛材料的反应设备进行简述,结合作者前期开展的微波合成β分子筛试验,分析并讨论微波和常规水热合成之间的主要区别以及反应机理,对微波加热技术未来应用于实际工业生产进行展望。     

粉煤灰合成分子筛的研究

在中国,粉煤灰合成分子筛是处理粉煤灰的一个重要方法,粉煤灰正成为沸石合成的一个重要原料.比较了水浴合成和微波合成制备分子筛的特点.XRD和SEM分析表明,微波晶化合成的沸石外观形状更加规则,均为圆形或者椭圆形的小球,且微波晶化合成的沸石分布均匀,结构致密.微波晶化可以快速晶化产生沸石,但随着晶化时间的推移,由于微波晶化的晶化反应太过剧烈,不利于核的增长.     

微波技术在分子筛领域的应用进展

本文综述了微波技术在分子筛研究领域中的应用，由于采用微波技术能够有效地促进反应分子间的相互作用，显著缩短化学反应的时间，降低能耗，因此微波技术在分子筛合成，分子筛膜制备以及分子筛改性等方面具有乐观的应用前景。     

煤矸石基沸石分子筛在水处理中的研究进展

介绍了目前以煤矸石为原料制备沸石分子筛的主要方法及优缺点,总结了煤矸石制备的沸石分子筛在去除水中氨氮、磷、有机物、重金属离子和氟等方面应用,并对"煤矸石→沸石分子筛→去除水中污染物"这条"以废治废"路线进行了系统的分析与展望。相比于传统的沸石分子筛制备路径,煤矸石制备沸石分子筛的原材料极易获取、合成成本低,合成产物对水中各类污染物质去除效果好。在今后的研究中,还应在煤矸石沸石分子筛的绿色制备,改性沸石分子筛和沸石分子筛+X复合材料的研发等方面继续深入,并拓展其在水处理领域的应用范围和途径。     

碱处理制备介孔-微孔沸石分子筛的影响因素及其应用研究进展

综述了碱处理制备介孔-微孔沸石分子筛的影响因素,包括碱处理条件、沸石分子筛硅铝比和模板剂对碱处理脱硅形成介孔的影响。评述了碱处理所制备介孔-微孔沸石分子筛在应用方面所取得的进展,重点介绍了它们在烷基化、异构化、裂化和醇烃化等催化反应中的应用。通过碱处理引入介孔可极大地缩短分子在沸石微孔道中的扩散距离,从而增强表观催化反应活性及提高催化剂的稳定性。提出了今后研究的重点为：阐明碱处理引入介孔的形成机理和碱处理对分子筛骨架结构、酸性的影响,拓展碱处理制备介孔-微孔沸石分子筛的应用 范围。     

微波场辅助离子交换制备NH_4~+-LSX型分子筛

采用微波离子交换法对Na-LSX型沸石分子筛进行NH+4交换。在固定液固比的条件下,考察了微波功率、交换液浓度、交换温度、液固比、时间以及次数对交换度的影响,并与传统水热离子交换法进行对比。得到了微波场辅助制备NH4-LSX型沸石分子筛的最佳工艺条件。     

沸石分子筛膜的合成与应用

综述了沸石分子筛膜的合成方法和应用。介绍了制备沸石分子筛膜最常州的水热合成法，包括晶种法和原位合成法，以及沸石分子筛膜在气体分离、渗透汽化和膜反应器中的应用。重点阐述了被除数广泛研究的MFI型分子筛膜的制备方法与应用。详细讨沦了多孔支撑体、晶体、水热合成条件以及合成液组成等因素对晶体生长和膜的形态以及对MFI型分子筛膜分离性能的影响，     

微波加热法向分子筛中引入稀土离子

微波加热法制备Ｌａ－ＮａＸ沸石分子筛催化剂;考察微波加热条件下,交换液浓度,交换时间、微波加热功率等因素对离子交换的影响;利用正交实验,寻找交换反应的最佳工艺条件,用对比实验与传统方法进行比较。     

固态离子交换制备Cu(Ⅰ)分子筛研究进展

固态离子交换是将金属离子引入分子筛结构中一种十分简单而有效的方法,它克服了溶液离子交换存在的诸多不利因素。本文介绍了固态离子交换制备Cu(Ⅰ)型分子筛的反应原理、制备条件的影响以及不同结构Cu(Ⅰ)型分子筛的应用。鉴于微波场中离子运动速率显著加快的特点,提出采用微波加热可以显著提高固态离子交换反应速率,对于提高Cu+离子交换度,消除残留CuCl的影响,获得高性能的Cu(Ⅰ)Y催化剂具有重要的应用价值。     

微波辐射下抗菌性沸石的制备

研究了微波辐射应用于沸石与ＡｇＮＯ３溶液的离子交换反应,制备抗菌性沸石。结果表明微波辐射可提高Ａｇ＾＋的交换度,缩短交换时间。     

多相催化剂的微波制备技术进展

对近年来微波技术在负载型金属催化剂、金属氧化物催化剂、负载型金属氯化物催化剂和离子改性分子筛制备中的应用进行了介绍,比较了微波加热和传统加热的实验结果。指出微波加热可以提高离子交换分子筛的交换度,可以使活性组分在载体表面实现快速均匀分散,并且促进金属氯化物与载体发生固态离子交换反应,从而提高催化剂的稳定性和反应活性。     

Mn-Containing AlPO-11 and SAPO-11 Catalysts for Simultaneous Isomerization and Dehydrogenation of n-Butane

Ferrierite-based catalysts have been evaluated in 1-butene isomerization using a continuous flow reactor operating under microwave and conventional heating conditions. The key feature of this study is the application of a single-mode microwave cavity, which can considerably enhance the heating efficiency compared to traditional microwave ovens. Our results demonstrate that the transformations of low polarity organic compounds over siliceous zeolites can be induced by microwave radiation. Despite the high power density in the utilized single-mode system, no structural degradation of the catalysts has been detected using FTIR and XRD. Our catalytic data confirm that medium-pore ferrierite is an effective isomerization catalyst providing high selectivity towards isobutene, particularly under conditions favoring the monomolecular reaction mechanism. The catalytic performance of ferrierite in the reactions carried out under microwave and conventional heating is very similar, although under the microwave irradiation this zeolite demonstrates a slightly higher yield and selectivity towards isobutene.     

微波辐射加热金属离子改性Hβ分子筛催化合成蒽醌

在微波辐射加热下用不同金属离子(Al3+、Ti4+、Fe3+)对Hβ分子筛进行改性,并将其用于催化苯与苯酐合成蒽醌。采用XRD、NH3-TPD和吡啶-IR对分子筛进行了表征。结果表明,微波辐射加热能提高分子筛的改性效率,改善其催化性能,且对分子筛晶体结构没有破坏作用。不同金属离子改性分子筛的催化效果差别很大,其中,0.5 mol/L的Al2(SO4)3溶液改性的Hβ分子筛催化效果最好,蒽醌产率38.87%,选择性92.78%。分子筛的表面酸性质对其催化性能有较大影响,催化剂表面的中强度酸是催化活性中心,L酸量与B酸量的比值对分子筛的催化性能有重要影响。     

Present and future synthesis challenges for zeolites

This work seeks to establish possible synthesis challenges in the zeolitic material field over the coming years. The choice may be subjective but it is worth reflecting on such an important question. The most pressing synthesis challenges in the opinion of the authors described in the following pages are: (1) elucidation of the nucleation and growth mechanism of zeolites; (2) controlling zeolite crystal size and growth habit; (3) preparation of extra-large pore zeolites; (4) synthesis of zeolitized mesoporous materials; (5) synthesis of chiral zeolites; (6) preparation and modification of layered zeolites; (7) and preparation of true molecular sieve membranes.     

TUN, IMF and -SVR Zeolites; Synthesis, Properties and Acidity

The effect of synthesis conditions on the preparation and properties of three novel zeolites TUN, IMF, and -SVR was investigated and compared with MFI. X-ray powder diffraction, infrared spectroscopy, chemical analysis, sorption measurements, and scanning electron microscopy were employed to characterize the textural and chemical properties of these zeolites. FTIR spectroscopy in combination with pyridine as probe molecule was used to describe the type, concentration and acid strength of these zeolites. Zeolite -SVR was synthesized with Si/Al ratios higher than 100 in contrast with TUN and IMF having Si/Al ratios about 20–30, respectively. TUN, MFI and IMF zeolites exhibit similar concentrations of Brønsted and Lewis acid sites and also similar acid strength of Brønsted sites. In contrast, the presence of one vacancy/unit cell in the case of -SVR zeolite substantially changes its acidic properties. Generally, zeolites TUN and IMF exhibit similar acidic properties in terms of acid strength and Brønsted to Lewis acid site ratio like MFI and due to their slightly larger pores higher activities in catalytic reactions are expected.     

Quick Activation of Optimized Zeolites with Microwave Heating and Utilization of Zeolites for Reusable Desiccant

Effectiveness of microwave heating in an activation treatment of zeolites was studied and utilization of zeolites for reusable desiccant was examined. X zeolite was chosen as a target material for its large adsorption capacity. Na-X zeolite easily caused a thermal runaway by microwave radiation of 500 W but Ca contained X zeolite merely reached ca. 573 K under the same conditions. Mixtures of Na-X and Ca-X with suitably mixed ratios did not cause the thermal runaway and their heating temperatures were controlled (>573 K) at will. Under the most suitable conditions, the mixture reached a dehydration degree of 92%. A degradation degree of adsorptive capacity of the mixture for water was examined after three treatments. The average degradation degree was 1.5% per treatment. The heating method is promising as a quick and easy technique to activate zeolite. By applying the method, the zeolites with suitable mixing ratios are usable as a reusable desiccant for home use.     

Effects of ultrasound on the synthesis of zeolites: a review

In this review, effects of ultrasound on the synthesis of different zeolites are studied. Ultrasound has been applied in crystallization because of its significant influences on the induction periods and nucleation. The effects of ultrasound assisted aging process for different zeolites compared with the effects of static aging, in some cases with microwave assisted aging, stirring aging and synthesis without any aging. Application of ultrasound can influence the size and morphology of the crystals, crystallization time and the crystallinity of the zeolites. The observations indicate that application of ultrasound can shorten the crystallization time. Application of ultrasound also improves crystallinity of the synthesized zeolites. Moreover, use of ultrasound assisted aging leads to altered morphologies and size of the particles.     

超稳Y型分子筛的制备、性能与工业应用

本文详尽地讨论了几种典型超稳Y型分子筛的制备过程、特点及工业应用情况,并对我国今后的工作提出自己的看法。