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Brungs, Attila J.; York, Andrew P. E.; Green, Malcolm L. H.

doi:10.1023/a:1019062608228

Cited by 94 publications

(76 citation statements)

References 11 publications

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“…While the former problem may be overcome by stabilising the zirconia by the addition of a species such as yttrium (with the added advantage that the Y increases the ability of the support to supply oxygen), the cost factor appears currently to mitigate against the use of Pt/ZrO 2 or equivalent materials. Green and his co-workers [30][31][32] have recently shown that it is possible to use several carbides as substitutes for supported metals as catalysts for dry reforming. We have examined the use of these carbides for dry reforming and have shown that the carbides only maintain their activities under conditions when the carbide is stable in the presence of the CO 2 of the reaction mixture and that requires there either to be back-mixing or some other way of ensuring that there is CO present at the beginning of the bed [33,34].…”

Section: Carbides As Substitutes For Supported Metal Catalystsmentioning

confidence: 99%

Natural gas reforming and CO2 mitigation

2005

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Section: Carbides As Substitutes For Supported Metal Catalystsmentioning

confidence: 99%

Natural gas reforming and CO2 mitigation

2005

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“…6,7,25 Many early transition metal carbides are good electrical and thermal conductors while possessing ultrahardness and very high melting points. 6,7 Furthermore, some of them are able to catalyze the transformation of hydrocarbons, 8,26 the conversion of methane to synthesis gas, 27,28 and desulfurization reactions. 8,23,29 Typically, early transition metals are very reactive, are not stable under chemical environments containing light elements, and exhibit a tendency to form compounds ͑oxides, nitrides, sulfides, carbides, phosphides͒.…”

Section: Introductionmentioning

confidence: 99%

“…The catalytic properties of metalcarbides can be drastically modified by adsorption of oxygen from the air or by reaction with O centers of oxide supports. 8,[26][27][28][29] In addition, oxygen also affects the performance of metal-carbide coatings used in the fabrication of mechanical and electronic devices. 6,7,21,22 The generation of an oxide film on top of the carbide can lead to a degradation of the conductivity and hardness of the system, 6,7 and oxocarbides can have interesting physical properties on their own.…”

Section: Introductionmentioning

confidence: 99%

Interaction of oxygen with ZrC(001) and VC(001): Photoemission and first-principles studies

et al. 2005

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High-resolution photoemission and first-principles density-functional calculations were used to study the interaction of oxygen with ZrC͑001͒ and VC͑001͒ surfaces. Atomic oxygen is present on the carbide substrates after small doses of O 2 at room temperature. At 500 K, the oxidation of the surfaces is fast and clear features for ZrO x or VO x are seen in the O͑1s͒, Zr͑3d͒, and V͑2p 3/2 ͒ core levels spectra, with an increase in the metal/carbon ratio of the samples. A big positive shift ͑1.3-1.6 eV͒ was detected for the C 1s core level in O / ZrC͑001͒, indicating the existence of strong O ↔ C or C↔ C interactions. A phenomenon corroborated by the results of first-principles calculations, which show a CZrZr hollow as the most stable site for the adsorption of O. Furthermore, the calculations also show that a C ↔ O exchange is exothermic on ZrC͑001͒, and the displaced C atoms bond to CZrZr sites. In the O / ZrC͑001͒ interface, the surface C atoms play a major role in determining the behavior of the system. In contrast, the adsorption of oxygen induces very minor changes in the C͑1s͒ spectrum of VC͑001͒. The O ↔ V interactions are stronger than the O ↔ Zr interactions, and O ↔ C interactions do not play a dominant role in the O / VC͑001͒ interface. In this system, C ↔ O exchange is endothermic. VC͑001͒ has a larger density of metal d states near the Fermi level than ZrC͑001͒, but the rate of oxidation of VC͑001͒ is slower. Therefore the O / ZrC͑001͒ and O / VC͑001͒ systems illustrate two different types of pathways for the oxidation of carbide surfaces.

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“…Bulk molybdenum carbide (Mo 2 C) catalysts have been reported by several groups to be active for CO 2 (dry) reforming of methane (DMR), and steam reforming of methane (SMR) [1][2][3][4][5]. Claridge et al [2] reported, for reforming in a packed bed reactor, that stability could be achieved only under conditions of elevated pressure (8.3 bar).…”

Section: Introductionmentioning

confidence: 99%