Oxidative coupling of methane catalyzed by rare earth oxides

Influence of Co2 on the Catalytic Performance Of La2O3/CeO2 and CaO/CeO2 Catalysts in the Oxidative Coupling of Methane

“…Before the beginning of the process the catalyst placed in the reactor was heated in dry helium for 30 min at the temperature of 1123 K. The weight of the catalyst was 400 mg (grain size 0.2-0.3 mm) and the temperature of the process was 1073 K. The reactor was fed by the mixture of the mole ratio CH 4 :O 2 = 3.75 which additionally contained helium and carbon dioxide (in the case the process was conducted with CO 2 ). The partial pressure of CO 2 was controlled by substituting helium with the carbon dioxide, thus the complete volumetric fl ow rate of the substrates was 156 cm 3 /min in all the tests. The products of the reaction and unreacted substrates were analyzed using the Agilent 6890N gas chromatograph equipped with two columns (molecular sieve 5A -the analysis of CO and O 2 and Hayesep Q -the analysis of H 2 , CO 2 , H 2 O and hydrocarbons) and the thermal conductivity detectors.…”

Raman spectra of R2O3 (R—rare earth) sesquioxides with C-type bixbyite crystal structure: A comparative study

“…A similar constant mode frequency was observed for a R-mode in the family R 2 CuO 4 (R-Pr, Nd, Sm, Gd). 49 To check which are the corresponding pure yttrium phonon modes in Y 2 O 3 , it is necessary to compare their frequencies with the ones for the lanthanide oxide with the closest unit cell parameter (or closest ionic radius, i.e., Ho) and to correct (normalize) its frequencies, accounting for the very 3 , proving the pure lanthanide origin of these vibrations (i.e., it is observed pure "isotope" effect). Even in the case of Sc 2 O 3 , despite the large difference between its unit cell parameter and those of the other compounds, the normalized frequencies still have such a value, so the corresponding peaks can be identified.…”

“…They are suitable to be used as electroluminescence 1 and cathodoluminescence 2 sources, catalysts for chemical organic reactions, 3,4 high-k gate dielectrics, 5 optical parts of high power lasers, 6 oxygen ion conducting electrolyte in solid oxide fuel cells, 7 and materials with strongly hydrophobic surface. 8 Depending on the type of the rare earth, five different crystal structures are known.…”

Structural characterization, thermoluminescence and EPR studies of Nd2O3:Co2+ nanophosphors

“…If the rare earth oxides were fabricated in the form of one dimensional nanostructure, they would have new properties as a result of both their marked shape-specific and quantum confinement effects. They would also act as electrically, magnetically, or optically functional host materials for rare earth ions in phosphor displays, waveguide devices, and for the active material in lasers [5].…”