Transition metal clusters in zeolites

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dc.contributor.advisor Dr. R. F. Howe en Yong, You Sing, 1958- en 2007-11-08T02:51:27Z en 2007-11-08T02:51:27Z en 1987 en
dc.identifier.citation Thesis (PhD--Chemistry)--University of Auckland. en
dc.identifier.uri en
dc.description Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. en
dc.description.abstract The adsorption and decomposition of Mo(CO)6 in zeolites X, Y, KL, Na-mordenite and Na-ZSM5 had been followed gravimetrically and spectroscopically. Mo(CO)6 was readily adsorbed into the pore structures of faujasites and zeolite KL but not into Na-mordenite and Na-ZSM5. Infrared studies showed that the adsorption produced a common adsorbed Mo(CO)6 species whose Oh symmetry was lowered. Subsequent activation in-vacuo at 100°C caused loss of approximately two carbonyl ligands per molybdenum which could be reversed by addition of carbon monoxide. Heating at or above 200°C caused complete and permanent decarbonylation. Zerovalent molybdenum clusters were produced within the pore structures of alkali metal-exchanged zeolites but for HY and LaY, oxidised molybdenum ions were also produced. Further uptake of Mo(CO)6 occurred on subsequent exposure of faujasite samples containing molybdenum to the vapour at room temperature. By repeated adsorption and decomposition of Mo(CO)6, zeolite sample containing up to 157 molybdenum per unit cell had been prepared. The carbon monoxide hydrogenation activity and selectivity of molybdenum-zeolite catalysts varied with zeolite structure and exchanged cation. Molybdenum-alkali metal-exchange zeolite catalysts were more selective to alkenes and liquefied petroleum gas range hydrocarbons (C2-C4) than molybdenum-HY and molybdenum-LaY catalysts. Using a combination of gas chromatography and infrared spectroscopy, a mechanism was postulated for the formation of hydrocarbons. en
dc.format Scanned from print thesis en
dc.language.iso en en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof PhD Thesis - University of Auckland en
dc.relation.isreferencedby UoA103063 en
dc.rights Whole document restricted. Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. en
dc.rights.uri en
dc.title Transition metal clusters in zeolites en
dc.type Thesis en Chemistry en The University of Auckland en Doctoral en PhD en
dc.subject.marsden Fields of Research::250000 Chemical Sciences en
dc.rights.holder Copyright: The author en
pubs.local.anzsrc 03 - Chemical Sciences en
dc.rights.accessrights en Faculty of Science en

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