Methane oxidation with low O2/CH4 ratios in the present of water: Combustion or reforming

Geng, Haojie; Yang, Zhongqing; Zhang, Li; Ran, Jingyu; Yan, Yunfei

doi:10.1016/j.enconman.2016.11.033

Cited by 15 publications

(5 citation statements)

References 35 publications

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“…This effect has been also observed in other works, and has been generally been linked to the weak adsorption potential that water molecules have on the surface of cobalt oxide [67,68]. In particular, Geng et al [69] observed a significant increase in the intensity of the DRIFTS absorption bands from hydroxyl groups in a Co/γ-Al 2 O 3 catalyst when water vapor was added to the feed. Additionally, H 2 O-TPD experiments in that work also proved that a high fraction of adsorbed water on the Co catalyst surface could be desorbed at low temperatures (<500 °C).…”

Section: Resultssupporting

confidence: 63%

Synthesis, Characterization and Kinetic Behavior of Supported Cobalt Catalysts for Oxidative after-Treatment of Methane Lean Mixtures

et al. 2019

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The present work addresses the influence of the support on the catalytic behavior of Co3O4-based catalysts in the combustion of lean methane present in the exhaust gases from natural gas vehicular engines. Three different supports were selected, namely γ-alumina, magnesia and ceria and the corresponding catalysts were loaded with a nominal cobalt content of 30 wt. %. The samples were characterized by N2 physisorption, wavelength dispersive X-ray fluorescence (WDXRF), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction with hydrogen and methane. The performance was negatively influenced by a strong cobalt-support interaction, which in turn reduced the amount of active cobalt species as Co3O4. Hence, when alumina or magnesia supports were employed, the formation of CoAl2O4 or Co–Mg mixed oxides, respectively, with a low reducibility was evident, while ceria showed a lower affinity for deposited cobalt and this remained essentially as Co3O4. Furthermore, the observed partial insertion of Ce into the Co3O4 lattice played a beneficial role in promoting the oxygen mobility at low temperatures and consequently the catalytic activity. This catalyst also exhibited a good thermal stability while the presence of water vapor in the feedstream induced a partial inhibition, which was found to be completely reversible.

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Section: Resultssupporting

confidence: 63%

Synthesis, Characterization and Kinetic Behavior of Supported Cobalt Catalysts for Oxidative after-Treatment of Methane Lean Mixtures

et al. 2019

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“…The corresponding material was very promising for methane oxidation purposes, as it presented good water resistance properties in wet CH 4 combustion [10]. Effect of water presence (either as gas humidity or as a combustion product) is suggested to cause deactivation mainly for Pd-based catalysts [11], due to the formation of OH groups, which block the interaction between methane and active sites [12], while a promotional effect is even reported for metal oxide materials (e.g., cobalt-manganese mixed oxides studied for methane combustion [13]. On the other hand, when testing water tolerance of CeO 2 -MOx catalysts (M = Cu, Mn, Fe, Co, and Ni) tested for CH 4 or CO oxidation, it seems that catalytic performance in the absence or presence of water depends on the mixed oxide [14].…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, when testing water tolerance of CeO 2 -MOx catalysts (M = Cu, Mn, Fe, Co, and Ni) tested for CH 4 or CO oxidation, it seems that catalytic performance in the absence or presence of water depends on the mixed oxide [14]. In another study [12], water effect during methane oxidation seems to also depends not only on active site (Cu or Co catalyst) but also on oxygen deficiency (O 2 /CH 4 ratios). More recently, investigation of reaction kinetics of wet lean methane combustion over Co 3 O 4 -and Pd/Co 3 O 4 catalysts outlined the beneficial contribution of Co 3 O 4 support towards tolerance to water poisoning [15].…”

Section: Introductionmentioning

confidence: 99%

Exploring Synthesis Approaches of Co-based Catalysts for the Efficient Oxidation of CH4 and CO

et al. 2022

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Co-based catalysts were synthesized and studied as novel oxidation catalysts, exploring and optimizing the effect of synthesis method on the redox behavior, the oxygen storage ability and thus the catalytic performance of the derived Co3O4 materials in the complete CH4 and/or CO oxidation reactions. Thus, a series of Co-based catalysts were synthesized applying either the precipitation and/or the hydrothermal method, using different precipitating agents (Na2CO3, NH3, urea or NaOH), Co precursor salt (nitrate or acetate) and finally varying the Co/Na ratio. In addition, the reaction time (6 or 24 h aging) was also investigated for the hydrothermally prepared Co3O4. The best catalysts for the CH4 oxidation are the precipitated Co3O4, using cobalt acetate as precursor salt and NaOH as precipitating agent, presenting the highest surface areas and the lowest Co3O4 particle sizes. On the other side, hydrothermally prepared cobalt oxides reveal higher performance for CO oxidation, with Co3O4 prepared with cobalt acetate, NaOH and low aging time shown as the optimum materials. The best catalysts were further promoted with incorporation of Pd (0.5wt.%) and explored for both reactions. The addition of Pd enhanced the activity of Co3O4 for CH4 oxidation, while Pd did not improve any further the catalyst performance for CO oxidation, presenting thus the same activity with pure cobalt oxides.

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“…For monometallic catalysts, such as Pt, Pd, Ag, Au, and Rh, their synthesis always employs calcination and reduction procedures. [15][16][17][18] These treatments help to build the crystal particles on the support surface. However, due to the differences in the metallic properties, the average particle diameter varies.…”

Section: Introductionmentioning

confidence: 99%

Effect of oxygen species and catalyst structure on the performance of methane activation over Pd–Pt catalysts

Geng

Yang

et al. 2022

React. Chem. Eng.

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Methane oxidation with low O2/CH4 ratios in the present of water: Combustion or reforming

Cited by 15 publications

References 35 publications

Synthesis, Characterization and Kinetic Behavior of Supported Cobalt Catalysts for Oxidative after-Treatment of Methane Lean Mixtures

Synthesis, Characterization and Kinetic Behavior of Supported Cobalt Catalysts for Oxidative after-Treatment of Methane Lean Mixtures

Exploring Synthesis Approaches of Co-based Catalysts for the Efficient Oxidation of CH4 and CO

Effect of oxygen species and catalyst structure on the performance of methane activation over Pd–Pt catalysts

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