Chemistry, like all the natural sciences, begins with the direct observation of nature¡ª in this case, of matter.16606-55-6, Name is (R)-4-Methyl-1,3-dioxolan-2-one, SMILES is O=C1OC[C@@H](C)O1, belongs to copper-catalyst compound. In a document, author is Negri, Chiara, introduce the new discover, COA of Formula: C4H6O3.
In situ X-ray absorption study of Cu species in Cu-CHA catalysts for NH3-SCR during temperature-programmed reduction in NO/NH3
Ammonia-mediated selective catalytic reduction (NH3-SCR) using Cu-exchanged chabazite zeolites as catalysts is one of the leading technologies for NOx removal from exhaust gases, with Cu-II/Cu-I redox cycles being the basis of the catalytic reaction. The amount of Cu-II ions reduced by NO/NH3 can be quantified by the consumption of NO during temperature-programmed reduction experiments (NO-TPR). In this article, we show the capabilities of in situ X-ray absorption near-edge spectroscopy (XANES), coupled with multivariate curve resolution (MCR) and principal component analysis (PCA) methods, in following Cu-II/Cu-I speciation during reduction in NO/NH3 after oxidation in NO/O-2 at 50 degrees C on samples with different copper loading and pretreatment conditions. Our XANES results show that during the NO/NH3 ramp Cu-II ions are fully reduced to Cu-I in the 50-290 degrees C range. The number of species involved in the process, their XANES spectra and their concentration profiles as a function of the temperature were obtained by MCR and PCA. Mixed ligand ammonia solvated complexes [Cu-II(NH3)(3)(X)](+) (X = OH-/O- or NO3-) are present at the beginning of the experiment, and are transformed into mobile [Cu-I(NH3)(2)](+) complexes: these complexes lose an NH3 ligand and become framework-coordinated above 200 degrees C. In the process, multiple Cu-II/Cu-I reduction events are observed: the first one around 130 degrees C is identified with the reduction of [Cu-II(NH3)(3)(OH/O)](+) moieties, while the second one occurs around 220-240 degrees C and is associated with the reduction of the ammonia-solvated Cu-NO3- species. The nitrate concentration in the catalysts is found to be dependent on the zeolite Cu loading and on the applied pretreatment conditions. Ammonia solvation increases the number of Cu-II sites available for the formation of nitrates, as confirmed by infrared spectroscopy.
The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 16606-55-6 is helpful to your research. COA of Formula: C4H6O3.
Reference:
Copper catalysis in organic synthesis – NCBI,
,Special Issue “Fundamentals and Applications of Copper-Based Catalysts”