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Effect of calcium addition on catalytic ethanol steam reforming of Ni/Al2O3: I. Catalytic stability, electronic properties and coking mechanism

Paper ID Volume ID Publish Year Pages File Format Full-Text
41303 45884 2011 10 PDF Available
Title
Effect of calcium addition on catalytic ethanol steam reforming of Ni/Al2O3: I. Catalytic stability, electronic properties and coking mechanism
Abstract

Ca-modified Ni/Al2O3 catalysts with various Ca loadings of 0, 3, 5 and 7 wt% were studied for low temperature catalytic ethanol steam reforming (ESR). Catalyst with 3 wt% of Ca remains stable at 673 K for at least 24 h, while 0 wt%, 5 wt% and 7 wt% Ca modified catalysts deactivate easily. The addition of Ca increases the particle size of active Ni which promotes the formation of un-reactive and encapsulating carbons, undermining the stability of highly loaded (7 wt%) Ca-modified Ni catalyst. XPS valence band shows that the presence of Ca increases the density of Ni 3d band valence electrons which helps in dissociation of methane and deactivates the catalysts, as in the case of nickel catalysts supported on 7 wt% of Ca on Al2O3. Excellent catalytic performance of 10Ni/3Ca-Al2O3 is due to the effective coke removal and the amorphous nature of coke deposition. Optimized Ca loading was found to play a critical role in coke removal, through its effect on Ni particle size, valence band of catalyst and steam gasification of coke.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (120 K)Download as PowerPoint slideHighlights► Effect of Ca on Ni/Al2O3 for low temperature ethanol steam reforming (ESR). ► Ca affects Ni particle size, electronic properties and steam gasification of coke. ► Optimal Ca loading is essential for the stability of catalyst in ESR.

Keywords
Steam reforming; Ethanol; Nickel catalyst; Calcium oxide; Stability; Coke mechanism; Surface OH groups; Water adsorption
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Effect of calcium addition on catalytic ethanol steam reforming of Ni/Al2O3: I. Catalytic stability, electronic properties and coking mechanism
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 407, Issues 1–2, 4 November 2011, Pages 145–154
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us