Estimation of Average Crystallites Size of Active Phase in Ceria-Supported Cobalt-Based Catalysts by Hydrogen Chemisorption vs TEM and XRD MethodsReport as inadecuate




Estimation of Average Crystallites Size of Active Phase in Ceria-Supported Cobalt-Based Catalysts by Hydrogen Chemisorption vs TEM and XRD Methods - Download this document for free, or read online. Document in PDF available to download.

Catalysis Letters

, Volume 146, Issue 10, pp 2173–2184

First Online: 18 August 2016Received: 10 June 2016Accepted: 05 August 2016

AbstractCobalt catalysts with CeO2 support, unpromoted and promoted with potassium were prepared by an impregnation method. Reduced catalysts were subjected to hydrogen chemisorption at different temperatures in the range of 313–453 K. Studies have shown that calculated Co crystallites size depends on the temperature of chemisorption. The average of size crystallites of the Co active phase obtained from the total and strong chemisorption data were compared with those from measurements by other techniques, TEM and XRD. The results of comparison allowed us to indicate the most suitable chemisorption temperature, different for unpromoted 383 K and potassium-promoted 413 K catalysts to determine the proper Co crystallites size of active phase, compatible with the crystallites size determined by the most objective method, i.e. by TEM measurements. In the case of small metal crystallites of active phase 4–5 nm the divergence of their average size determined by hydrogen chemisorption and TEM methods and particularly by the XRD method is definitely higher than that in the case of larger crystallites ~12 nm.

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AbstractOpen image in new windowKeywordsHeterogeneous catalysis Electron microscopy Nanostructure Crystallites size Hydrogen chemisorption XRD Cobalt-based catalysts Electronic Supplementary MaterialThe online version of this article doi:10.1007-s10562-016-1843-1 contains supplementary material, which is available to authorized users.

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Author: Grzegorz Słowik - Anna Gawryszuk-Rżysko - Magdalena Greluk - Andrzej Machocki

Source: https://link.springer.com/







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