DC Field | Value | Language |
---|---|---|
dc.contributor.author | Kim, CW | - |
dc.contributor.author | Jung, KJ | - |
dc.contributor.author | Heo, NH | - |
dc.contributor.author | Kim, SH | - |
dc.contributor.author | Hong, SB | - |
dc.contributor.author | Seff, K | - |
dc.date.accessioned | 2016-04-01T08:38:26Z | - |
dc.date.available | 2016-04-01T08:38:26Z | - |
dc.date.created | 2009-08-23 | - |
dc.date.issued | 2009-04-02 | - |
dc.identifier.issn | 1932-7447 | - |
dc.identifier.other | 2009-OAK-0000018096 | - |
dc.identifier.uri | https://oasis.postech.ac.kr/handle/2014.oak/28432 | - |
dc.description.abstract | Five single crystals of vacuum-dehydrated Ni2+-exchanged zeolite Y (Ni-Y) were variously prepared by the exchange of Na-Y or K-Y (Na-71- or K-71-Si121Al71O384, Si/Al = 1.69) with Ni2+ using flowing aqueous 0.05 M Ni(NO3)(2) at 294 or 353 K, followed by vacuum dehydration at 2.0 x 10(-6) Torr and 623 or 723 K. Their crystal structures and chemical compositions were determined using synchrotron X-radiation and energy dispersive X-ray (EDX) analyses to give Ni-n-Y, where 25.3 <= n <= 34.1 per unit cell: [NiuMvHw[Ni8O4 center dot xH(2)O](y)[Al(OH)(4)](z)l [Si121+zAl71-zO384]-FAU, where 21.4 <= n <= 24.2, M = Na and/or Ca, 3.3 <= v <= 13.1, 9.5 <= w <= 21.6, 2 <= x <= 4, 0.3 <= y <= 3.2, and 0 <= z <= 2.5. In each of the five crystal structures (space group Fd(3)m; mean a = 24.47 A), Ni2+ is found at sites I, I', a second I', II', and sometimes 11; unexpectedly, Na+ and Ca2+ are found at another site It. Two extra-framework oxygen positions (O-f), one in the sodalite cavity and the other nearby in the supercage, are seen on 3-fold axes in all crystals. They bond to Al3+ and Ni2+ ions in the sodalite cavities to form Al(OeH)(4)(-) and Ni-8(O-e)center dot xH(2)O(e)(8+) clusters with Ni-4(O-e)(4) cores, and with framework oxygens (O-f) to give trigonal bipyramidal Ni(O-f)(3)(O-e)(2)(2+) and trigonal pyramidal Ni(O-f)(3)(O-e)(2)(2+.) At site I (centers of double 6-rings) in the Na-Y crystal that was Ni2+-exchanged at 294 K, similar to 14 Ni2+ ions per unit cell each coordinate octahedrally to six framework oxygen atoms. The Ni2+ ions at the first F site are 3-coordinate near planar in all crystals. The Ni2+ ions at the second Y site are members of the Ni4O4 cores, tetrahedrally distorted cubes with Ni-O = 2.199(13) angstrom and O-Ni-O = 79.6(9)degrees in a representative crystal; these Ni2+ ions are distorted octahedral with three O-e's of the cluster and three Of's. The Ni2+ ions at sites II' and II are 3-, 4-, or 5-coordinate. Al(OH)(4)(-) from framework dealumination centers some sodalite cavities in four of the five crystals; their number increased with both ion-exchange and dehydration temperatures, suggesting that dealumination occurred during both processes. The number of Ni-2+ ions per unit cell increases with Ni2+-exchange temperature and is greater with K-Y than with Na-Y, perhaps because the larger K+ ions are more loosely held. The leaving cation affects the Ni2+ distribution over the available sites, perhaps via the level of Ni2+-exchange. Both a greater degree of Ni2+-exchange and a higher dehydration temperature cause more Ni8O4 center dot xH(2)O(8+) clusters to form, leaving fewer Ni2+ ions at sites I and II. As more Ni8O4 center dot xH(2),O8+ formed, more H+ ions were produced. Some H+ and some 3- and 4-coordinate Ni2+ ions are easily accessible for catlysis. | - |
dc.description.statementofresponsibility | X | - |
dc.language | English | - |
dc.publisher | AMER CHEMICAL SOC | - |
dc.relation.isPartOf | JOURNAL OF PHYSICAL CHEMISTRY C | - |
dc.title | Crystal Structures of Vacuum-Dehydrated Ni2+-Exchanged Zeolite Y (FAU, Si/Al=1.69) Containing Three-Coordinate Ni2+, Ni8O4 center dot xH(2)O(8+), x <= 4, Clusters with Near Cubic Ni4O4 Cores, and H+ | - |
dc.type | Article | - |
dc.contributor.college | 환경공학부 | - |
dc.identifier.doi | 10.1021/JP810846X | - |
dc.author.google | Kim, CW | - |
dc.author.google | Jung, KJ | - |
dc.author.google | Heo, NH | - |
dc.author.google | Kim, SH | - |
dc.author.google | Hong, SB | - |
dc.author.google | Seff, K | - |
dc.relation.volume | 113 | - |
dc.relation.issue | 13 | - |
dc.relation.startpage | 5164 | - |
dc.relation.lastpage | 5181 | - |
dc.contributor.id | 10077624 | - |
dc.relation.journal | JOURNAL OF PHYSICAL CHEMISTRY C | - |
dc.relation.index | SCI급, SCOPUS 등재논문 | - |
dc.relation.sci | SCI | - |
dc.collections.name | Journal Papers | - |
dc.type.rims | ART | - |
dc.identifier.bibliographicCitation | JOURNAL OF PHYSICAL CHEMISTRY C, v.113, no.13, pp.5164 - 5181 | - |
dc.identifier.wosid | 000264591900020 | - |
dc.date.tcdate | 2019-02-01 | - |
dc.citation.endPage | 5181 | - |
dc.citation.number | 13 | - |
dc.citation.startPage | 5164 | - |
dc.citation.title | JOURNAL OF PHYSICAL CHEMISTRY C | - |
dc.citation.volume | 113 | - |
dc.contributor.affiliatedAuthor | Hong, SB | - |
dc.identifier.scopusid | 2-s2.0-65249101639 | - |
dc.description.journalClass | 1 | - |
dc.description.journalClass | 1 | - |
dc.description.wostc | 26 | - |
dc.description.scptc | 24 | * |
dc.date.scptcdate | 2018-05-121 | * |
dc.type.docType | Article | - |
dc.subject.keywordPlus | FAUJASITE-TYPE ZEOLITES | - |
dc.subject.keywordPlus | NICKEL-OXIDE CLUSTERS | - |
dc.subject.keywordPlus | CATION DISTRIBUTIONS | - |
dc.subject.keywordPlus | MAGNETIC-PROPERTIES | - |
dc.subject.keywordPlus | SODALITE CAVITIES | - |
dc.subject.keywordPlus | SORPTION COMPLEX | - |
dc.subject.keywordPlus | RESIDUAL WATER | - |
dc.subject.keywordPlus | NO REDUCTION | - |
dc.subject.keywordPlus | PH 4.3 | - |
dc.subject.keywordPlus | DIFFRACTION | - |
dc.relation.journalWebOfScienceCategory | Chemistry, Physical | - |
dc.relation.journalWebOfScienceCategory | Nanoscience & Nanotechnology | - |
dc.relation.journalWebOfScienceCategory | Materials Science, Multidisciplinary | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.relation.journalResearchArea | Chemistry | - |
dc.relation.journalResearchArea | Science & Technology - Other Topics | - |
dc.relation.journalResearchArea | Materials Science | - |
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