{"title":"水热合成碱阳离子水镁铝硅酸盐分子筛","authors":"Dongyuan Zhao, Larry Kevan, Rosemarie Szostak","doi":"10.1016/S0144-2449(97)00134-6","DOIUrl":null,"url":null,"abstract":"<div><p>Heulandite molecular sieves with a Si/Al ratio of 3.2 ~ 3.8 have been synthesized hydrothermally in the presence of the alkali cations Li<sup>+</sup>; Li<sup>+</sup>, K<sup>+</sup>; and Na<sup>+</sup>, K<sup>+</sup> at 190 °C at autogenous pressure. They have been characterized by X-ray powder diffraction and scanning electron micrographs. Heulandites can be formed in the Li<sup>+</sup> and Na<sup>+</sup>, K<sup>+</sup> cation systems only with ~10 wt% seed crystals. But heulandite can be synthesized in the presence of Li<sup>+</sup>, K<sup>+</sup> cations without seed crystals. The formation of heulandite-type zeolites occurs over a narrow crystallization field and depends on the Si/Al ratio, the OH<sup>−</sup>/Si ratio, and on the presence of seed crystals. Scanning electron micrographs show a thin-plate topology for the crystals. Heulandite is thermally unstable for calcination beyond 350 ~ 450 °C.</p></div>","PeriodicalId":23983,"journal":{"name":"Zeolites","volume":"19 5","pages":"Pages 366-369"},"PeriodicalIF":0.0000,"publicationDate":"1997-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0144-2449(97)00134-6","citationCount":"13","resultStr":"{\"title\":\"Hydrothermal synthesis of alkali cation heulandite aluminosilicate molecular sieves\",\"authors\":\"Dongyuan Zhao, Larry Kevan, Rosemarie Szostak\",\"doi\":\"10.1016/S0144-2449(97)00134-6\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Heulandite molecular sieves with a Si/Al ratio of 3.2 ~ 3.8 have been synthesized hydrothermally in the presence of the alkali cations Li<sup>+</sup>; Li<sup>+</sup>, K<sup>+</sup>; and Na<sup>+</sup>, K<sup>+</sup> at 190 °C at autogenous pressure. They have been characterized by X-ray powder diffraction and scanning electron micrographs. Heulandites can be formed in the Li<sup>+</sup> and Na<sup>+</sup>, K<sup>+</sup> cation systems only with ~10 wt% seed crystals. But heulandite can be synthesized in the presence of Li<sup>+</sup>, K<sup>+</sup> cations without seed crystals. The formation of heulandite-type zeolites occurs over a narrow crystallization field and depends on the Si/Al ratio, the OH<sup>−</sup>/Si ratio, and on the presence of seed crystals. Scanning electron micrographs show a thin-plate topology for the crystals. Heulandite is thermally unstable for calcination beyond 350 ~ 450 °C.</p></div>\",\"PeriodicalId\":23983,\"journal\":{\"name\":\"Zeolites\",\"volume\":\"19 5\",\"pages\":\"Pages 366-369\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1997-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/S0144-2449(97)00134-6\",\"citationCount\":\"13\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Zeolites\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0144244997001346\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zeolites","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0144244997001346","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Hydrothermal synthesis of alkali cation heulandite aluminosilicate molecular sieves
Heulandite molecular sieves with a Si/Al ratio of 3.2 ~ 3.8 have been synthesized hydrothermally in the presence of the alkali cations Li+; Li+, K+; and Na+, K+ at 190 °C at autogenous pressure. They have been characterized by X-ray powder diffraction and scanning electron micrographs. Heulandites can be formed in the Li+ and Na+, K+ cation systems only with ~10 wt% seed crystals. But heulandite can be synthesized in the presence of Li+, K+ cations without seed crystals. The formation of heulandite-type zeolites occurs over a narrow crystallization field and depends on the Si/Al ratio, the OH−/Si ratio, and on the presence of seed crystals. Scanning electron micrographs show a thin-plate topology for the crystals. Heulandite is thermally unstable for calcination beyond 350 ~ 450 °C.