Dubey, Anjani and Kolekar, Sadhu K and Gopinath, Chinnakonda S. (2016) C-H Activation of Methane to Formaldehyde on Ce1-xZrxO2 Thinfilms : A step to bridge the material gap. Chemcatchem, 8. pp. 3650-3656. ISSN 1867-389

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Abstract

Ce1-xZrxO2 (ceria-zirconia - CZ) thin films were prepared by a combination of sol-gel andspin coating method and evaluated for C-H activation of methane in a molecular beam setup towards bridging the material gap. C-H activation of methane begins at 950 K, and Ce-rich CZ composition displays high selectivity (4-12 %) to partiallyoxidized product, formaldehyde.10-12 % selectivity towards HCHOwith 1.6 % methane conversion was observed with methane-rich CH4:O2 reactants compositions at 1050 K. Low contact time conditions, prevalent under molecular beam experimental conditions, could be a possible reason for HCHO formation. While combustion products were observed instantly upon shining reactants mixture on CZ surfaces, up to 20 s delay was observed to begin formaldehyde generation underscoringthe oxygen vacancy migration predominantly contributes to the rate determining step and diffusion controlled nature. A burst in HCHO generation at the point of molecular beam open, after every beam close conditions, underscores the diffusion of oxygen vacancies to the surface which is the reason for HCHO formation. Kinetic results also indicate the necessity of reduction sites for HCHO generation.

Item Type: Article
Subjects: Catalysis and Surface Science
Divisions: UNSPECIFIED
Depositing User: Manoj Kumar ghosalya
Date Deposited: 17 Jan 2017 06:34
Last Modified: 17 Jan 2017 09:38
URI: http://ncl.csircentral.net/id/eprint/2514

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