scholarly journals Total Oxidation of Methane on Oxide and Mixed Oxide Ceria-Containing Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 427
Author(s):  
Marius Stoian ◽  
Vincent Rogé ◽  
Liliana Lazar ◽  
Thomas Maurer ◽  
Jacques C. Védrine ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Methane Oxidation ◽  
Catalytic Combustion ◽  
Oxygen Vacancies ◽  
High Heat ◽  
Atmospheric Environment ◽  
Total Oxidation ◽  
Oxidation Of Methane ◽  
Ceo2 Sample ◽  
Crystallographic Facets

Methane, discovered in 1766 by Alessandro Volta, is an attractive energy source because of its high heat of combustion per mole of carbon dioxide. However, methane is the most abundant hydrocarbon in the atmosphere and is an important greenhouse gas, with a 21-fold greater relative radiative effectiveness than CO2 on a per-molecule basis. To avoid or limit the formation of pollutants that are dangerous for both human health and the atmospheric environment, the catalytic combustion of methane appears to be one of the most promising alternatives to thermal combustion. Total oxidation of methane, which is environmentally friendly at much lower temperatures, is believed to be an efficient and economically feasible way to eliminate pollutants. This work presents a literature review, a statu quo, on catalytic methane oxidation on transition metal oxide-modified ceria catalysts (MOx/CeO2). Methane was used for this study since it is of great interest as a model compound for understanding the mechanisms of oxidation and catalytic combustion on metal oxides. The objective was to evaluate the conceptual ideas of oxygen vacancy formation through doping to increase the catalytic activity for methane oxidation over CeO2. Oxygen vacancies were created through the formation of solid solutions, and their catalytic activities were compared to the catalytic activity of an undoped CeO2 sample. The reaction conditions, the type of catalysts, the morphology and crystallographic facets exposing the role of oxygen vacancies, the deactivation mechanism, the stability of the catalysts, the reaction mechanism and kinetic characteristics are summarized.

CATALYTIC ACTIVITY FOR METHANE OXIDATION OF GOETHITE SUPPORTED ON ALUMINA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4249-4254 ◽  
Author(s):  
KEI-ICHIRO MURAI ◽  
KOHEI TOMITA ◽  
SUGURU TOJO ◽  
TOSHIHIRO MORIGA ◽  
ICHIRO NAKABAYASHI
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Methane Oxidation ◽  
Model Experiment ◽  
The Other ◽  
Catalytic Activities ◽  
Surface Areas ◽  
Oxidation Of Methane ◽  
Other Hand ◽  
Specific Surface Areas

Two kinds of α- Fe 2 O 3 catalysts supported on χ- Al 2 O 3 and γ- Al 2 O 3 were synthesized. α- Fe 2 O 3 was prepared from α- FeOOH . As a model experiment, an investigation was made with the oxidation of methane. As all catalysts with various Fe contents supported on χ- Al 2 O 3 with various Fe contents had higher specific surface areas than those supported on γ- Al 2 O 3, α- Fe 2 O 3/χ- Al 2 O 3 catalyst has higher catalytic activities than α- Fe 2 O 3/γ- Al 2 O 3 catalyst. From SEM-EDS analyses, it is concluded that in α- Fe 2 O 3/χ- Al 2 O 3 catalyst, α- Fe 2 O 3 exists mainly on the surface of the support, because of flatness of the surface of χ- Al 2 O 3. On the other hand, in the case of α- Fe 2 O 3/γ- Al 2 O 3 catalyst, as the surface of support, γ- Al 2 O 3, is uneven, α- Fe 2 O 3 do not partially exist on the surface but in the pores.

Effect of Pt nanoparticle size on the specific catalytic activity of Pt/SiO2 and Pt/TiO2 in the total oxidation of methane and n-butane

2010 ◽  
Vol 59 (9) ◽  
pp. 1713-1719 ◽  
Author(s):  
A. Yu. Stakheev ◽  
A. M. Gololobov ◽  
I. E. Beck ◽  
G. O. Bragina ◽  
V. I. Zaikovsky ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nanoparticle Size ◽  
Pt Nanoparticle ◽  
Total Oxidation ◽  
Oxidation Of Methane ◽  
Specific Catalytic Activity

scholarly journals Influence of the support on rhodium speciation and catalytic activity of rhodium-based catalysts for total oxidation of methane

2020 ◽  
Vol 10 (17) ◽  
pp. 6035-6044
Author(s):  
Yu Zhang ◽  
Peter Glarborg ◽  
Martin Peter Andersson ◽  
Keld Johansen ◽  
Thomas Klint Torp ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Total Oxidation ◽  
Oxidation Of Methane ◽  
Zeolite Supports

In Rh-catalysts for CH4-oxidation, Si-rich zeolite supports yield the more active Rh2O3 nanoparticle form and the highest SO2 and H2O tolerance.

scholarly journals XANES studies of zirconia-ceria/Ni during partial/total methane oxidation

2014 ◽  
Vol 70 (a1) ◽  
pp. C130-C130
Author(s):  
Rebeca Bacani ◽  
Márcia Fantini ◽  
Tereza Martins ◽  
Susana Larrondo ◽  
Diego Lamas
Keyword(s):  
Methane Oxidation ◽  
Ccd Camera ◽  
Structural Features ◽  
Oxygen Storage ◽  
Total Oxidation ◽  
Oxidation Of Methane ◽  
Pluronic P123 ◽  
Release Capacity ◽  
Mesoporous Support ◽  
Temperature Programmed

Zirconia-ceria solid-solutions are extensively used as promoters for three-way catalysts, in addition, these materials can be used as anodes in solid oxide fuel cells (SOFCs) operated with hydrocarbons. The structural features of ZrO2-CeO2 materials in combination with oxygen storage/release capacity (OSC) are crucial for various catalytic reactions. The direct use of hydrocarbons as fuel for the SOFC (instead of pure H2), without the necessity of reforming and purification reactors can improve global efficiency of the system. The samples preparation method was developed using Zr and Ce chloride precursors, HCl aqueous solution, Pluronic P123, NH4OH and a Teflon autoclave. The samples were dried and calcined, until 540°C. The NiO impregnation was made with an ethanol dispersion of Ni(NO3)×6H2O, calcinated in air until 350°C for 2 hours. In-situ XANES experiments are capable to evaluate the reduction/oxidation potencial of Ni and Ce species in ZrO2-CeO2/Ni samples during partial/total methane oxidation and reduction reactions with H2. The experiments at the Ni K-edge/Ce L3-edge were collected at the LNLS D06A-DXAS beam line in transmission mode, using a Si(111) monochromator and a CCD camera as detector. The data were acquired during a series of temperature programmed reduction steps (TPR), under a 5% H2/He until 600°C, and mixtures of 20%CH4:5%O2/He with 2:1, 1:1 and 1:2 ratios. After each process with CH4 and O2, a TPR procedure was performed in order to evaluate the reduction capacity of the sample after reactions with CH4. The results demonstrated that NiO embedded in the porous ZrO2-CeO2 matrix, reduces at lower temperatures than standard NiO, measured in the same conditions, revealing that the mesoporous support improves the reduction of impregnated NiO. For both edges, there was formation of H2 during partial methane oxidation at 600°C. The total oxidation of methane was observed in lower temperatures (500°C). These results reveal that a high ceria content (90%) could be a great candidate for the SOFC anode.

scholarly journals Total oxidation of methane over Pd/Al2O3 at pressures from 1 to 10 atm

2020 ◽  
Vol 10 (16) ◽  
pp. 5480-5486
Author(s):  
Carl-Robert Florén ◽  
Cansunur Demirci ◽  
Per-Anders Carlsson ◽  
Derek Creaser ◽  
Magnus Skoglundh
Keyword(s):  
Methane Oxidation ◽  
Multiscale Simulations ◽  
Total Oxidation ◽  
Oxidation Of Methane ◽  
Temperature Programmed ◽  
Monolith Catalyst ◽  
Kinetics Of

The kinetics of total methane oxidation over a 0.15 wt% Pd/Al2O3 monolith catalyst has been measured during temperature programmed methane oxidation experiments at total pressures from 1 to 10 atm and compared with multiscale simulations.

Sulfation of a PdO(101) methane oxidation catalyst: mechanism revealed by first principles calculations

2019 ◽  
Vol 9 (1) ◽  
pp. 232-240 ◽  
Author(s):  
Ryan Lacdao Arevalo ◽  
Susan Meñez Aspera ◽  
Hiroshi Nakanishi
Keyword(s):  
Catalytic Activity ◽  
Methane Oxidation ◽  
First Principles ◽  
Sulfur Poisoning ◽  
Oxidation Catalyst ◽  
First Principles Calculations ◽  
Oxidation Of Methane

PdO efficiently catalyzes the oxidation of methane but suffers tremendously from sulfur poisoning that lowers its catalytic activity.

scholarly journals Oscillatory Behaviour of Ni Supported on ZrO2 in the Catalytic Partial Oxidation of Methane as Determined by Activation Procedure

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2495
Author(s):  
Daniela Pietrogiacomi ◽  
Maria Cristina Campa ◽  
Ida Pettiti ◽  
Simonetta Tuti ◽  
Giulia Luccisano ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Partial Oxidation ◽  
Active Sites ◽  
Direct Reduction ◽  
Partial Oxidation Of Methane ◽  
Catalytic Partial Oxidation ◽  
Oxidation Of Methane ◽  
Short Contact Time ◽  
Oxidation Reduction ◽  
Ni Species

Ni/ZrO2 catalysts, active and selective for the catalytic partial oxidation of methane to syngas (CH4-CPO), were prepared by the dry impregnation of zirconium oxyhydroxide (Zhy) or monoclinic ZrO2 (Zm), calcination at 1173 K and activation by different procedures: oxidation-reduction (ox-red) or direct reduction (red). The characterization included XRD, FESEM, in situ FTIR and Raman spectroscopies, TPR, and specific surface area measurements. Catalytic activity experiments were carried out in a flow apparatus with a mixture of CH4:O2 = 2:1 in a short contact time. Compared to Zm, Zhy favoured the formation of smaller NiO particles, implying a higher number of Ni sites strongly interacting with the support. In all the activated Ni/ZrO2 catalysts, the Ni–ZrO2 interaction was strong enough to limit Ni aggregation during the catalytic runs. The catalytic activity depended on the activation procedures; the ox-red treatment yielded very active and stable catalysts, whereas the red treatment yielded catalysts with oscillating activity, ascribed to the formation of Niδ+ carbide-like species. The results suggested that Ni dispersion was not the main factor affecting the activity, and that active sites for CH4-CPO could be Ni species at the boundary of the metal particles in a specific configuration and nuclearity.

scholarly journals Highly Dispersed Pd Species Supported on CeO2 Catalyst for Lean Methane Combustion: The Effect of the Occurrence State of Surface Pd Species on the Catalytic Activity

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 772
Author(s):  
Yanxiong Liu ◽  
Changhua Hu ◽  
Longchun Bian
Keyword(s):  
Catalytic Activity ◽  
Oxygen Vacancies ◽  
Methane Combustion ◽  
Pd Nanoparticles ◽  
High Concentration ◽  
Ch4 Combustion ◽  
Highly Active ◽  
Δ Phase ◽  
Occurrence State ◽  
Comprehensive Characterization

The correlation between the occurrence state of surface Pd species of Pd/CeO2 for lean CH4 combustion is investigated. Herein, by using a reduction-deposition method, we have synthesized a highly active 0.5% PdO/CeO2-RE catalyst, in which the Pd nanoparticles are evenly dispersed on the CeO2 nanorods CeO2-R. Based on comprehensive characterization, we have revealed that the uniformly dispersed Pd nanoparticles with a particle size distribution of 2.3 ± 0.6 nm are responsible for the generation of PdO and PdxCe1−xO2−δ phase with –Pd2+–O2−–Ce4+– linkage, which can easily provide oxygen vacancies and facilitate the transfer of reactive oxygen species between the CeO2-R and Pd species. As a consequence, the remarkable catalytic activity of 0.5% Pd/CeO2-RE is related to the high concentration of PdO species on the surface of the catalyst and the synergistic interaction between the Pd species and the CeO2 nanorod.

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