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Selective methoxylation of α-pinene to α-terpinyl methyl ether over Al3+ ion-exchanged clays

dc.contributor.authorCatrinescu, C.
dc.contributor.authorFernandes, C.
dc.contributor.authorCastilho, P.
dc.contributor.authorBreen, C.
dc.date.accessioned2021-03-29T14:03:41Z
dc.date.available2021-03-29T14:03:41Z
dc.date.issued2015
dc.description.abstractIn this study, we report the use of clay-based catalysts in the methoxylation of -pinene, for the selective synthesis of -terpinyl methyl ether, TME. The main reaction products and intermediates were identified by GC–MS. The reaction conditions (stirring rate and catalystload)that afford a kinetic regime were estab lished. SAz-1 (Cheto, Arizona, USA) source clay and a montmorillonite (SD) from Porto Santo, Madeira Archipelago, Portugal, were modified by ion-exchange with Al3+ to produce catalysts with markedly different acidities and textural properties. The catalysts based on the high layer-charge SAz-1 montmo rillonite proved to be the most active. Ion-exchange with Al3+, followed by thermal activation at 150 ◦C, afforded the highest number of Brønsted acid sites – a significant proportion of which were located in the clay gallery – and this coincided with the maximum catalytic activity. The influence of various reac tion conditions, to maximize -pinene conversion and selectivity, was studied over AlSAz-1. When the reaction was performed for 1 h at 60 ◦C, the conversion reached 65% with 65% selectivity towards the mono-ether, TME. Similar conversions and selectivities required up to 50 h over zeolites and other solid acid catalysts. The kinetic dependencies of this reaction on temperature and reagent concentration, over the selected clays were also investigated. It was established that, in the temperature and reagent con centration regime studied, the reaction was first order with respect to -pinene. The apparent activation energies over the two catalysts, calculated from Arrhenius plots, were almost identical at 72 kJ mol−1.pt_PT
dc.description.versioninfo:eu-repo/semantics/publishedVersionpt_PT
dc.identifier.citationCatrinescu, C., Fernandes, C., Castilho, P., & Breen, C. (2015). Selective methoxylation of α-pinene to α-terpinyl methyl ether over Al3+ ion-exchanged clays. Applied Catalysis A: General, 489, 171-179.pt_PT
dc.identifier.doi10.1016/j.apcata.2014.10.028pt_PT
dc.identifier.urihttp://hdl.handle.net/10400.13/3217
dc.language.isoengpt_PT
dc.peerreviewedyespt_PT
dc.publisherElsevierpt_PT
dc.relationPTDC/CTMCER/121295/2010pt_PT
dc.relationPEst OE/QUI/UI0619/2011pt_PT
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/pt_PT
dc.subjectIon-exchanged clayspt_PT
dc.subjectClay aciditypt_PT
dc.subjectCatalysispt_PT
dc.subjectPinenept_PT
dc.subjectMethoxylationpt_PT
dc.subjectTerpinyl methyl ethept_PT
dc.subject.pt_PT
dc.subjectFaculdade de Ciências Exatas e da Engenhariapt_PT
dc.subjectCentro de Química da Madeira
dc.titleSelective methoxylation of α-pinene to α-terpinyl methyl ether over Al3+ ion-exchanged clayspt_PT
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage179pt_PT
oaire.citation.startPage171pt_PT
oaire.citation.titleApplied Catalysis A: Generalpt_PT
oaire.citation.volume489pt_PT
person.familyNameFernandes
person.familyNameCastilho
person.givenNameCesar
person.givenNamePaula C
person.identifierA-4412-2013
person.identifier.ciencia-id6D15-8C69-A2E0
person.identifier.orcid0000-0001-9289-9962
person.identifier.orcid0000-0002-8303-4286
person.identifier.scopus-author-id14064572200
rcaap.rightsopenAccesspt_PT
rcaap.typearticlept_PT
relation.isAuthorOfPublication482857a3-4e6d-4453-bfc1-afb17ff8ce2a
relation.isAuthorOfPublicationd84fd917-438e-43bf-ac6f-256562481c05
relation.isAuthorOfPublication.latestForDiscoveryd84fd917-438e-43bf-ac6f-256562481c05

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