Microporous Materials最新文献_第7页

Water-assisted ionic conductance of zeolites with ZSM-5 structure ZSM-5结构沸石的水助离子电导率

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00023-0

S.D. Mikhailenko , S. Kaliaguine , E. Ghali

引用次数: 20

Micropore size distribution of octahedral molecular sieves (OMS) 八面体分子筛(OMS)微孔尺寸分布

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00017-5

Chi-Lin O'Young , Robert A. Sawicki , Steven L. Suib

引用次数: 13

CIT-4: The first synthetic analogue of brewsterite CIT-4:第一个合成的brewsterite类似物

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00036-9

Shervin Khodabandeh, Gary Lee, Mark E. Davis

引用次数: 9

Recrystallization of magadiite varieties isomorphically substituted with aluminum to MFI and MEL zeolites 镁辉石品种与铝同构取代成MFI和MEL沸石的再结晶

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00027-8

Gabriella Pál-Borbély , Hermann K. Beyer , Yoshimichi Kiyozumi , Fuijio Mizukami

引用次数: 45

Synthesis of MCM-41 materials: an in situ FTIR study MCM-41材料的合成:原位FTIR研究

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00033-3

V.L. Zholobenko, S.M. Holmes, C.S. Cundy, J. Dwyer

引用次数: 61

Titanium silicates, M3HTi4O4(SiO4)3·4H2O (M=Na+, K+),with three-dimensional tunnel structures for the selective removal of strontium and cesium from wastewater solutions 具有三维隧道结构的硅酸钛M3HTi4O4(SiO4)3·4H2O (M=Na+， K+)可选择性去除废水中的锶和铯

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00022-9

Elizabeth A. Behrens, Abraham Clearfield

{"title":"Titanium silicates, M3HTi4O4(SiO4)3·4H2O (M=Na+, K+),with three-dimensional tunnel structures for the selective removal of strontium and cesium from wastewater solutions","authors":"Elizabeth A. Behrens, Abraham Clearfield","doi":"10.1016/S0927-6513(97)00022-9","DOIUrl":"10.1016/S0927-6513(97)00022-9","url":null,"abstract":"<div>The ion exchange behavior of a sodium and a potassium titanosilicate towards Cs+ and Sr2+ was studied. The materials of interest in this study are titanium and silicon structural analogs of the mineral pharmacosiderite. Pharmacosiderite is a non-aluminosilicate molecular sieve with the framework composition [Fe4(OH)4 (AsO4)3]−.5H2O. For the titanosilicate analogs, the framework arrangement of silicate tetrahedra and titanium octahedra create three-dimensional structures with water molecules and charge-neutralizing cations located in the face-centers. Distribution coefficient (Kd) measurements showed that the potassium titanosilicate removed at least 97% of the Sr2+ from a groundwater simulant that also contained ppm levels of Ca2+, Mg2+, K+, Cs+ and Na+. Similarly, the sodium phase removed about 98% Cs+ from the groundwater solution. These preliminary Kd values provide an indication that these exchangers may act as potential Cs+ and Sr2+ sorbers for groundwater remediation applications. The sodium and potassium phases were also tested as potential exchangers for Cs+ and Sr2+ in different nuclear waste simulants. While the sodium phase showed little to no preference for Cs+ in highly acidic or basic solutions containing large concentrations of NaNO3, the potassium phase yielded a Sr2+ Kd of around 7100 ml g−1 in 2.5 M NaNO3/l M NaOH solutions, and a Kd of 3500 ml g−1 for a solution containing 5 M NaNO3/l M NaOH.</div>","PeriodicalId":100926,"journal":{"name":"Microporous Materials","volume":"11 1","pages":"Pages 65-75"},"PeriodicalIF":0.0,"publicationDate":"1997-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0927-6513(97)00022-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75803779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 66

Synthesis of new aluminophosphate materials with the FAU and AFR structure-types 具有FAU和AFR结构的新型磷酸铝材料的合成

Microporous Materials Pub Date : 1997-08-01 DOI: 10.1016/S0927-6513(97)00021-7

L. Sierra, J. Patarin, J.L. Guth

引用次数: 9

A comparative study of the kinetics of adsorption and desorption of benzene and o-xylene in H-MCM-22-, H-ZSM-5- and H-beta-zeolites H-MCM-22-、H-ZSM-5-和h - β沸石对苯和邻二甲苯的吸附和解吸动力学的比较研究

Microporous Materials Pub Date : 1997-07-01 DOI: 10.1016/S0927-6513(97)00014-X

Rune Wendelbo , Rolando Roque-Malherbe

{"title":"A comparative study of the kinetics of adsorption and desorption of benzene and o-xylene in H-MCM-22-, H-ZSM-5- and H-beta-zeolites","authors":"Rune Wendelbo , Rolando Roque-Malherbe","doi":"10.1016/S0927-6513(97)00014-X","DOIUrl":"10.1016/S0927-6513(97)00014-X","url":null,"abstract":"<div>The kinetics of adsorption and desorption of benzene and o-xylene in H-MCM-22-, H-ZSM-5- and H-beta-zeolites have been studied by means of in situ FTIR. The adsorbents were passed over the activated zeolite wafer, while the spectrum was continuously scanned for about 13 min. During this period adsorption equilibrium was attained for benzene on all three zeolites and for o-xylene on H-beta, whereas only about one-fourth of the expected capacity, or 0.23 mmol g−1 of o-xylene had been adsorbed on H-MCM-22 within 3 min, increasing negligibly in the following 10 min. After 14 h, the amount of o-xylene adsorbed on H-MCM-22 had increased to 0.39 mmol g−1. The adsorption of o-xylene on MCM-22 could thus be resolved into a rapid and a slow process, with the rapid process having a diffusion coefficient typical of small molecules in wide pore zeolites, and the slow process having a diffusion coefficient in the same range as for o-xylene in MFI-zeolites. It was shown that the rapid process represented interaction with hydroxyls of the external surface, and it was thus quantitatively important only because the MCM-22 sample consisted of very small crystals. Since small crystals are typical of MCM-22, the results present an explanation of literature reports indicating the existence of a 12-ring pore system. It also explains why MCM-22 cannot be used for the separation of xylene isomers like the 10-ring MFI-zeolites. Desorption experiments showed that the o-xylene adsorbed on the external silanols was also the first to be desorbed at 298 K, whereas o-xylene adsorbed on internal bridged hydroxyls was quantitatively desorbed in the range 350–460 K.</div>","PeriodicalId":100926,"journal":{"name":"Microporous Materials","volume":"10 4","pages":"Pages 231-246"},"PeriodicalIF":0.0,"publicationDate":"1997-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0927-6513(97)00014-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81246339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Synthesis and structure of a novel microporous titanosilicate (UND-1) with a chemical composition of Na2.7K5.3Ti4Si12O364H2O 化学成分为Na2.7K5.3Ti4Si12O364H2O的新型微孔二氧化钛(un -1)的合成与结构

Microporous Materials Pub Date : 1997-07-01 DOI: 10.1016/S0927-6513(97)00020-5

Xinsheng Liu , Maoyu Shang, J. Kerry Thomas

引用次数: 17

Gel shrinkage and nutrient addition in unstirred batch zeolite A reaction systems 未搅拌间歇式沸石A反应体系中的凝胶收缩和营养物加入

Microporous Materials Pub Date : 1997-07-01 DOI: 10.1016/S0927-6513(97)00008-4

M. Fulcher , J. Warzywoda, A. Sacco Jr., R.W. Thompson, A.G. Dixon

引用次数: 3