Oxidative dehydrogenation of ethane over lanthana: Actual nature of the active phase

Bernal, S.; Martin, G.A.; Moral, P.; Perrichon, V.

doi:10.1007/bf00774725

Cited by 37 publications

(7 citation statements)

References 16 publications

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“…Evidence from the literature also suggests that rare earth metal oxide-based catalysts involving CeO 2 demonstrated high selectivity for ethane ODH, with the improved performance attributed to their basicity and high thermal stability. 22 It seems that promotion of h-BN with CeO 2 −ZrO 2 had this effect, as the selectivity was slightly higher than observed for the h-BN catalyst. However, the promoter significantly lowered the catalyst activity, and thus the overall effect of CeO 2 −ZrO 2 addition was not beneficial.…”

Section: Resultsmentioning

confidence: 92%

“…This is equivalent to making the oxygen atoms less reactive. Evidence from the literature also suggests that rare earth metal oxide-based catalysts involving CeO 2 demonstrated high selectivity for ethane ODH, with the improved performance attributed to their basicity and high thermal stability . It seems that promotion of h-BN with CeO 2 –ZrO 2 had this effect, as the selectivity was slightly higher than observed for the h-BN catalyst.…”

Section: Results and Discussionmentioning

confidence: 96%

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Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Loiland

Zhao

Patel

et al. 2019

Ind. Eng. Chem. Res.

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Oxidative dehydrogenation (ODH) of ethane and propane feeds has been examined under a variety of temperatures, flow rates, and gas compositions in a fixed bed reactor using boron nitride-based catalysts either promoted with various metal oxides or supported on silica. Tests performed at low conversion in the presence of a large amount of N 2 diluent indicated that addition of MgO to boron nitride (BN) led to a ∼10-fold increase in alkane conversion, with a drop in the C 2 −C 3 olefin selectivity from 90% to 79%. Testing using concentrated feeds with small amounts of diluent (3%) indicated that metal-oxide promoted BN catalysts could maintain C 2 −C 3 olefin selectivities as high as 65% at high alkane conversion (∼60%). Catalyst productivity values under these conditions approached 16 kg olefins kg cat −1 h −1 . Under nondilute conditions, the catalysts appear to act as initiators of radical reactions at the surface, after which the radicals desorb into the gas phase and undergo propagation steps.

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Section: Resultsmentioning

confidence: 92%

Section: Results and Discussionmentioning

confidence: 96%

Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Loiland

Zhao

Patel

et al. 2019

Ind. Eng. Chem. Res.

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“…It seems that the presence of a high concentration of oxidized carbon, presumably La 2 CO 2 CO 3 and formate-type species on the support in the Ni/La 2 O 3 catalyst, plays an important role in enhancing reaction rate. It should be mentioned that, unlike the carbonate on strong basic oxides, i.e., alkali and alkaline earth oxides, the carbonate species (in the form of La 2 O 2 CO 3 ) on La 2 O 3 (of a moderate basicity) only have moderate stability and tend to be mobile and partially decomposed at the temperatures applied for the reforming reaction. , A recent isotopic labeling study shows that the oxygen species from the La 2 O 2 CO 3 participate, to a significant extent, in the formation of CO and CO 2 with interaction of the CH 4 /O 2 mixture, presumably via exchange between gaseous O 2 and the oxygen species from the La 2 O 2 CO 3 . Recent preliminary isotopic experiments conducted in this laboratory have also confirmed that a large amount of atomic oxygen species, originating from La 2 O 2 CO 3 , participate in CO formation in the CH 4 /CO 2 reaction.…”

Section: Discussionmentioning

confidence: 99%

Comparative Study of Carbon Dioxide Reforming of Methane to Synthesis Gas over Ni/La₂O₃and Conventional Nickel-Based Catalysts

et al. 1996

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Carbon dioxide reforming of methane to synthesis gas was studied by employing a Ni/La2O3 catalyst as well as conventional nickel-based catalysts, i.e., Ni/γ-Al2O3, Ni/CaO/γ-Al2O3, and Ni/CaO. It is observed that, in contrast to conventional nickel-based catalysts, which exhibit continuous deactivation with time on stream, the rate of reaction over the Ni/La2O3 catalyst increases during the initial 2−5 h and then tends to be essentially invariable with time on stream. X-ray photoelectron spectroscopy (XPS) studies show that the surface carbon on spent Ni/Al2O3 catalyst is dominated by −C−C− species that eventually block the entire Ni surface, leading to total loss of activity. The surface carbon on the working Ni/La2O3 catalyst is found to consist of −C−C− species and a large amount of oxidized carbon. Both XPS and secondary ion mass spectrometry results reveal that a large fraction of surface Ni on the working Ni/La2O3 catalyst is not shielded by carbon deposition. FTIR studies reveal that the enhancement of the rate of reaction over the Ni/La2O3 catalyst during the initial 2−5 h of reaction correlates well with increasing concentrations of La2O2CO3 and formate species on the support, suggesting that these species may participate in the surface chemistry to produce synthesis gas. It is proposed that the interaction between nickel and lanthanum species creates a new type of synergetic sites at the Ni−La2O3 interfacial area, which offer active and stable performance of carbon dioxide reforming of methane to synthesis gas over the stated catalyst.

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“…The increase of reaction rate at the beginning of the experiment suggests a slow process where an equilibrium in La 2 O 2 CO 3 and for others carbonaceous species on the surface nickel crystallites is established. La 2 O 2 CO 3 phase has a moderate stability and can be partially decomposed at reaction temperatures [21,22]. This species can be considered as an oxygen dynamic tampon.…”

Section: Effect Of Lanthana Content On the Supportmentioning

confidence: 99%

Development of biogas reforming Ni-La-Al catalysts for fuel cells

Benito

Garcia

Ferreira-Aparicio

et al. 2007

Journal of Power Sources

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Oxidative dehydrogenation of ethane over lanthana: Actual nature of the active phase

Cited by 37 publications

References 16 publications

Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Comparative Study of Carbon Dioxide Reforming of Methane to Synthesis Gas over Ni/La₂O₃and Conventional Nickel-Based Catalysts

Development of biogas reforming Ni-La-Al catalysts for fuel cells

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Oxidative dehydrogenation of ethane over lanthana: Actual nature of the active phase

Cited by 37 publications

References 16 publications

Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Boron-Containing Catalysts for the Oxidative Dehydrogenation of Ethane/Propane Mixtures

Comparative Study of Carbon Dioxide Reforming of Methane to Synthesis Gas over Ni/La2O3and Conventional Nickel-Based Catalysts

Development of biogas reforming Ni-La-Al catalysts for fuel cells

Contact Info

Product

Resources

About

Comparative Study of Carbon Dioxide Reforming of Methane to Synthesis Gas over Ni/La₂O₃and Conventional Nickel-Based Catalysts