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Dry reforming of methane with carbon dioxide over NiO–MgO–ZrO2☆

Paper ID Volume ID Publish Year Pages File Format Full-Text
53258 46957 2016 8 PDF Available
Title
Dry reforming of methane with carbon dioxide over NiO–MgO–ZrO2☆
Abstract

•Melt impregnation to obtain NiO–MgO–ZrO2 catalysts with 2–35 Ni and Mg.•Ni and Mg are homogeneously distributed as oxides on the zirconia.•Highly dispersed Ni0 and a NiO–MgO solid solution are present on the support.•Coking includes growth of MWCNT and graphitic carbon, encapsulating Ni0 particles.

NiO–MgO–ZrO2 catalysts were synthesized via a melt impregnation technique on a zirconia support with equimolar amounts of Ni and Mg in the range of 2–35 mol%. The catalysts were characterized by TPDA, TPR, PXRD, TEM and EDX. The catalysts are basic in nature and contain both tetragonal and monoclinic zirconia. After impregnation, Ni and Mg are homogeneously distributed over the zirconia support in oxidic form. After reduction of the composite system, metallic Ni is highly dispersed on the support together with a solid solution of NiO–MgO present. The prepared NiO–MgO–ZrO2 catalysts show a high activity in the dry reforming of methane at 1123 K and atmospheric pressure. At high Ni and Mg contents, the catalysts are subject to severe coking leading to pronounced deactivation. From TEM investigations, a coking mechanism is proposed including the growth of filamentous carbon followed by formation of graphitic carbon, partly encapsulating metallic Ni particles. An optimum stability can be achieved in a small compositional corridor with Ni and Mg contents of 8–20 mol%. In this composition range, the presence of MgO leads to a suppression of carbon formation, especially when compared to Ni supported on Mg-free zirconia. According to their activity and stability depending on the Ni- and Mg-contents, the catalysts were assigned to three categories: (I) low activity and high stability, (II) high activity and some stability and (III) high activity, but low stability.

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Keywords
NiO–MgO–ZrO2; Synthesis gas; Dry reforming; Coking; Sintering
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Dry reforming of methane with carbon dioxide over NiO–MgO–ZrO2☆
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Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Today - Volume 270, 15 July 2016, Pages 68–75
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
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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