Study of Catalytic Methane Oxidation Over Pd Supported on Nanocrystalline CeO2: Effects of Calcination and Pd Loading

2001 ◽  
Vol 676 ◽  
Author(s):  
Seung H. Oh ◽  
Michael L. Everett ◽  
Gar B. Hoflund ◽  
Johannes Seydel ◽  
Horst W. Hahn
Keyword(s):  
Catalytic Oxidation ◽  
Methane Oxidation ◽  
Catalyst Activity ◽  
Pd Catalyst ◽  
Oxidation Of Methane ◽  
Heating And Cooling ◽  
Enhanced Activity ◽  
Nanocrystalline Ceria ◽  
Catalytic Methane Oxidation

ABSTRACTThe catalytic oxidation of methane was studied over palladium supported on nanocrystalline ceria. Three palladium weight loadings (1, 5, and 10 wt%) were tested after calcining at 500 °C, at 280 °C and after no calcination at all. For the 5 and 10 wt% loadings, the 280 °C-calcined and non-calcined catalysts exhibit enhanced activity after several heating and cooling cycles. Calcining these same catalysts at 500 °C results in a systematic decline in activity. For all pretreatments the 1 wt% Pd catalyst exhibits decreasing activity. For the 5 and 10 wt% Pd loadings, the non-calcined catalysts are more active than the 280 °C-calcined catalysts, which are more active than the 500 °C-calcined catalysts. For the 1 wt% Pd catalyst, the opposite is true. The catalyst activity improves as the Pd loading is increased.

Comparison of Nanocrystalline and Polycrystalline Oxide Supports for Catalytic Oxidation of Methane

1997 ◽  
Vol 497 ◽  
Author(s):  
Horst H. Hahn ◽  
Heiko Hesemann ◽  
William S. Epling ◽  
Gar B. Hoflund
Keyword(s):  
Catalytic Oxidation ◽  
Methane Oxidation ◽  
Weight Basis ◽  
Oxide Supports ◽  
Oxidation Of Methane ◽  
Better Than

ABSTRACTNanocrystalline and polycrystalline ZrO2, CeO2 and Mn3O4 without and with 5 wt% Pd have been tested for methane oxidation. The nanocrystalline catalysts perform better than the polycrystalline catalysts on a weight basis. Nanocrystalline (n)-CeO2 performs much better than n-ZrO2, and both perform much better than polycrystalline (P)-CeO2 and P-ZrO2. 5 wt% Pd/n-ZrO2 is the best catalyst tested, but 5 wt% Pd/n-CeO2 performs nearly as well. A 20 wt% Ag/p-ZrO2 and a 20 wt% Ag/n-ZrO2 catalyst were also tested. The Ag yields a significant improvement over the bare supports, but not as much so as Pd.

Evolution of Pd catalyst structure and activity during catalytic oxidation of methane and ethane

2014 ◽  
Vol 485 ◽  
pp. 1-9 ◽  
Author(s):  
V.Yu. Bychkov ◽  
Yu.P. Tyulenin ◽  
A.Ya. Gorenberg ◽  
S. Sokolov ◽  
V.N. Korchak
Keyword(s):  
Catalytic Oxidation ◽  
Pd Catalyst ◽  
Catalyst Structure ◽  
Oxidation Of Methane ◽  
Structure And Activity

scholarly journals Catalytic Oxidation of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 944
Author(s):  
Anil C. Banerjee
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Catalytic Oxidation ◽  
Energy Sources ◽  
Oxidation Of Methane

Methane (the major component of natural gas) is one of the main energy sources for gas-powered turbines for power generation, and transport vehicles [...]

scholarly journals Lanthanum modified Fe-ZSM-5 zeolites for selective methane oxidation with hydrogen peroxide

2021 ◽  
Author(s):  
Songmei Sun ◽  
Alexandra Barnes ◽  
Xiaoxiao Gong ◽  
Richard Lewis ◽  
Nicholas F. Dummer ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Methane Oxidation ◽  
Partial Oxidation ◽  
Partial Oxidation Of Methane ◽  
Ambient Conditions ◽  
Oxidation Of Methane

Selective partial oxidation of methane to methanol under ambient conditions is a great challenge in chemistry. Iron modified ZSM-5 catalysts are shown to be effective for this reaction using H2O2...

scholarly journals Unraveling reaction networks behind the catalytic oxidation of methane with H2O2 over a mixed-metal MIL-53(Al,Fe) MOF catalyst

2018 ◽  
Vol 9 (33) ◽  
pp. 6765-6773 ◽  
Author(s):  
Ágnes Szécsényi ◽  
Guanna Li ◽  
Jorge Gascon ◽  
Evgeny A. Pidko
Keyword(s):  
Dft Calculations ◽  
Catalytic Oxidation ◽  
Metal Organic Framework ◽  
Reaction Networks ◽  
Reaction Paths ◽  
Mixed Metal ◽  
Oxidation Of Methane ◽  
Metal Organic ◽  
Periodic Dft Calculations ◽  
Periodic Dft

Reaction paths underlying the catalytic oxidation of methane with H2O2 over an Fe containing MIL-53(Al) metal–organic framework were studied by periodic DFT calculations.

scholarly journals Subgroup Characteristics of Marine Methane-Oxidizing ANME-2 Archaea and Their Syntrophic Partners as Revealed by Integrated Multimodal Analytical Microscopy

2018 ◽  
Vol 84 (11) ◽  
Author(s):  
Shawn E. McGlynn ◽  
Grayson L. Chadwick ◽  
Ariel O'Neill ◽  
Mason Mackey ◽  
Andrea Thor ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methane Oxidation ◽  
Three Dimensional ◽  
Fluorescence Labeling ◽  
Anaerobic Oxidation Of Methane ◽  
Methane Seep ◽  
Bacterial Populations ◽  
Symbiotic Associations ◽  
Iron Mineral ◽  
Oxidation Of Methane

ABSTRACTPhylogenetically diverse environmental ANME archaea and sulfate-reducing bacteria cooperatively catalyze the anaerobic oxidation of methane oxidation (AOM) in multicelled consortia within methane seep environments. To better understand these cells and their symbiotic associations, we applied a suite of electron microscopy approaches, including correlative fluorescencein situhybridization-electron microscopy (FISH-EM), transmission electron microscopy (TEM), and serial block face scanning electron microscopy (SBEM) three-dimensional (3D) reconstructions. FISH-EM of methane seep-derived consortia revealed phylogenetic variability in terms of cell morphology, ultrastructure, and storage granules. Representatives of the ANME-2b clade, but not other ANME-2 groups, contained polyphosphate-like granules, while some bacteria associated with ANME-2a/2c contained two distinct phases of iron mineral chains resembling magnetosomes. 3D segmentation of two ANME-2 consortium types revealed cellular volumes of ANME and their symbiotic partners that were larger than previous estimates based on light microscopy. Polyphosphate-like granule-containing ANME (tentatively termed ANME-2b) were larger than both ANME with no granules and partner bacteria. This cell type was observed with up to 4 granules per cell, and the volume of the cell was larger in proportion to the number of granules inside it, but the percentage of the cell occupied by these granules did not vary with granule number. These results illuminate distinctions between ANME-2 archaeal lineages and partnering bacterial populations that are apparently unified in their ability to perform anaerobic methane oxidation.IMPORTANCEMethane oxidation in anaerobic environments can be accomplished by a number of archaeal groups, some of which live in syntrophic relationships with bacteria in structured consortia. Little is known of the distinguishing characteristics of these groups. Here, we applied imaging approaches to better understand the properties of these cells. We found unexpected morphological, structural, and volume variability of these uncultured groups by correlating fluorescence labeling of cells with electron microscopy observables.

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