Infrared and X-ray photoelectron spectroscopy studies of carbon monoxide adsorbed on silica-supported cobalt catalysts

1984 ◽  
Vol 80 (4) ◽  
pp. 841 ◽  
Author(s):  
Kimihiko Sato ◽  
Yasunobu Inoue ◽  
Isao Kojima ◽  
Eizo Miyazaki ◽  
Iwao Yasumori
Keyword(s):  
Carbon Monoxide ◽  
Photoelectron Spectroscopy ◽  
Cobalt Catalysts ◽  
X Ray ◽  
Supported Cobalt Catalysts ◽  
Spectroscopy Studies

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

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3174 ◽  
Author(s):  
Andoni Choya ◽  
Beatriz de Rivas ◽  
Jose Ignacio Gutiérrez-Ortiz ◽  
Juan Ramón González-Velasco ◽  
Rubén López-Fonseca
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Cobalt Content ◽  
Cobalt Catalysts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Supported Cobalt Catalysts ◽  
Temperature Programmed ◽  
Cobalt Species

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.

An intensity modulated fiber-optic carbon monoxide sensor based on Ag/Co-MOF in-situ coated thin-core fiber

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lian Wang ◽  
Juncheng Zhou ◽  
Yuhao Chen ◽  
Liu Xiao ◽  
Guojia Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Monoxide ◽  
Photoelectron Spectroscopy ◽  
Fiber Optic ◽  
Temperature Stability ◽  
Single Mode ◽  
X Ray ◽  
Intensity Modulated ◽  
Core Fiber

Abstract An intensity modulated fiber-optic carbon monoxide (CO) sensor by integrating in-situ solvothermal-growth Ag/Co-MOF sensing film is fabricated and evaluated. The Michelson interference sensing structure is composed of single-mode fiber (SMF), enlarged taper, thin-core fiber (TCF), and Ag film as the reflector. Ag/Co-MOF was coated on the cladding of the TCF as the sensing material, and the enlarged taper is located between TCF and SMF as the coupler. The structure, morphology, compositions and thermal stability of the Ag/Co-MOF sensing film were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), etc. The sensitivity of the sensor is 0.04515 dB/ppm, and the fitting parameter of the CO concentration is 0.99876. In addition, the sensor has the advantages of good selectivity, good signal and temperature stability, and it has potential application in trace CO detection.

Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

2011 ◽  
Vol 89 (7) ◽  
pp. 845-853 ◽  
Author(s):  
Sadok Letaief ◽  
Wendy Pell ◽  
Christian Detellier
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Fine Particles ◽  
Raw Materials ◽  
Carbon Monoxide Oxidation ◽  
Functional Materials ◽  
Metallic State ◽  
Oxidation Reactions ◽  
X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

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