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Methane dry reforming on Ni loaded hydroxyapatite and fluoroapatite

Paper ID Volume ID Publish Year Pages File Format Full-Text
44136 46004 2007 11 PDF Available
Title
Methane dry reforming on Ni loaded hydroxyapatite and fluoroapatite
Abstract

Calcium-hydroxyapatite and calcium-fluoroapatite loaded with different amounts of nickel were synthesized and characterized by several techniques including scanning electron microscopy, temperature programmed reduction (TPR), UV–visible–NIR and XPS spectroscopy. Three types of nickel species were detected in the two series of catalysts (i) Ni2+ ions exchanged with Ca2+ ions of the apatite framework. This Ni2+/Ca2+ exchange seems to be restricted to nickel loadings inferior to 1 wt% Ni, (ii) small particles of NiO exhibiting strong interactions with the carriers (for x > 1 wt% Ni) and (iii) large particles of NiO which appear at high loadings. The distribution of the nickel between these three hosting sites depends on the nature of the apatite. For instance the amount of exchanged Ni2+ ions in Ni(1)/CaHAp is twice more important than in Ni(1)/CaFAp.The Ni(x)/CaHAp and Ni(x)/CaFAp catalysts were tested in methane dry reforming with CO2. Methane conversion at 600 °C, increases with the nickel loading up to x = 4 where the activity is around the thermodynamic equilibrium (78%) and H2/CO ratio close to 1. These results were confirmed by the investigation of the catalysts activity versus the temperature. Carbon deposition on the catalysts was found to also increase with nickel loading but without provoking any significant decay of the activity after 4 h on stream. The encouraging results achieved were attributed to the synergy between the basic properties of the apatites, their aptitude to chemisorb CO2 and the catalytic features of the supported nickel.

Graphical abstractNi(x)/CaHAP and Ni(x)/CaFAP were prepared and characterized using electron microscopy, TPR, UV–visible–NIR and XPS spectroscopy. Three species of nickel were identified and their distribution in the catalysts varied with the nature of the apatite. At all temperatures, the catalysts performance in methane dry reforming, was managed by thermodynamics and appeared as good as that of Mg–Ni/Al2O3.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Methane dry reforming; Ni loaded calcium-hydroxyapatite; Ni loaded calcium-fluoroapatite; XRD; IR; DRS; XPS and TPR
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Methane dry reforming on Ni loaded hydroxyapatite and fluoroapatite
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 317, Issue 2, 7 February 2007, Pages 299–309
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
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Any Questions? feel free to contact us