Understanding the spatial distribution of coke deposition within bimodal micro-/mesoporous catalysts using a novel sorption method in combination with pulsed-gradient spin-echo NMR

Li M Chua, Iain Hitchcock, R S Fletcher, E M Holt, John Lowe, S P Rigby

Research output: Contribution to journalArticle

2 Citations (Scopus)
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Abstract

A new method for the determination of the spatial distribution of metal surface area within bimodal micro-/mesoporous solids has been developed. This novel technique involves incorporating a nonane pre-adsorption stage between two successive chemisorption experiments. This method has been used to probe the distribution of platinum amongst the micropores and mesopores of a range of bi-functional PtH-MFI catalysts, each possessing differing surface acidities, which have been used for benzene alkylation with ethane. It has been found that the catalyst with the lowest Si/Al ratio, and thus highest number of acid sites, also possessed the largest metal surface area within its microporosity. This catalyst was also the one that deactivated most rapidly, with coke being deposited predominantly within the micropore network. This was attributed to the bi-functional mechanism for coke formation at higher temperatures. Pulsed-gradient spin-echo NMR has also been used to show that a combination of higher mesopore platinum concentration and higher mass transport rates facilitated greater coke deposition within the mesoporosity.
Original languageEnglish
Pages (from-to)260-265
Number of pages6
JournalJournal of Catalysis
Volume286
DOIs
Publication statusPublished - Feb 2012

Fingerprint

coke
Coke
sorption
Spatial distribution
Sorption
echoes
spatial distribution
Nuclear magnetic resonance
Platinum
catalysts
gradients
nuclear magnetic resonance
Catalysts
metal surfaces
platinum
Metals
nonanes
microporosity
Microporosity
Ethane

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Understanding the spatial distribution of coke deposition within bimodal micro-/mesoporous catalysts using a novel sorption method in combination with pulsed-gradient spin-echo NMR. / Chua, Li M; Hitchcock, Iain; Fletcher, R S; Holt, E M; Lowe, John; Rigby, S P.

In: Journal of Catalysis, Vol. 286, 02.2012, p. 260-265.

Research output: Contribution to journalArticle

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