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, L. M., Hitchcock, I., Fletcher, R. S., Holt, E. M., Lowe, J. and Rigby, S. P., 2012. 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. Journal of Catalysis, 286, pp. 260-265.
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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.
|Creators||Chua, L. M., Hitchcock, I., Fletcher, R. S., Holt, E. M., Lowe, J. and Rigby, S. P.|
|Departments||Faculty of Science > Chemistry|
Faculty of Engineering & Design > Chemical Engineering
|Publisher Statement||Chua_-_Spatial_distribution_of_coke.pdf: NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Catalysis. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Catalysis, Vol. 286, Feb 2012, DOI:10.1016/j.jcat.2011.11.012|
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