Search results for " methane"
showing 10 items of 146 documents
A Three-Component Palladium-Catalyzed Oxidative CC Coupling Reaction: A Domino Process in Two Dimensions
2013
One‐pot synthesis of [2+2]‐helicate‐like macrocycle and 2+4‐μ 4 ‐oxo tetranuclear open frame complexes: Chiroptical properties and asymmetric oxidati…
2020
Constitution and conductivity of metalloporphyrin tapes
2020
Supported Single Atom Catalysts for C−H Activation: Selective C−H Oxidations, Dehydrogenations and Oxidative C−H/C−H Couplings
2021
Biindenyls, Biindenylides, and Diindeno‐Fused Heterocycles from Oxidative Coupling of 1‐ and 2‐Indanone
1988
1- and 2-indanone are transformed into the corresponding enolates and oxidatively coupled to yield 1,4-diketones providing easy access to a series of biindenyls, diindeno-fused heterocycles, and biindenylides. Biindenyle, Biindenylide und Diindeno-kondensierte Heterocyclen durch oxidative Kupplung von 1- und 2-Indanon 1- und 2-Indanon werden in die Enolate ubergefuhrt und oxidativ zu 1,4-Diketonen gekuppelt. Diese bieten einen einfachen Zugang zu einer Reiher von Biindenylen, Diindeno-kondensierten Heterocyclen und Biindenyliden.
Theoretical EHT study of oxidative coupling of methane on pure MgO and MgO doped with Li and Na
1991
Abstract On the basis of Extended Huckel Theory, empirical studies on the oxidative coupling of methane with MgO pure and MgO doped with Li and Na are presented. The results obtained from the two-dimensional energy surfaces calculated for the interaction between linear clusters of these oxides and the methane molecule show a qualitative agreement with the experimental behaviour reported for these catalysts. The calculated activation energy barriers are in accord with the relative activities of these oxides (Li/MgO > Na/ MgO > MgO) and are of the same order of magnitude as the experimentally determined activation energies.
Pd/Co3O4 catalyst for CH4 emissions abatement: study of SO2 poisoning effect
2007
A catalyst with 0.7 wt% Pd load supported over Co3O4 oxide was investigated in the methane oxidation by operating under CH4/O2 stoichiometric conditions. The effect of the noble metal addition on the activity of bare Co3O4 was evaluated. Samples were characterized by BET, XRD, TPR and XPS analyses. The SO2 poisoning of Pd catalyst and Co3O4 was studied by performing CH4 oxidation tests under stoichiometric conditions in SO2 (1 ppm or 10 ppm). Experiments evidenced that in our conditions the low amount of SO2 doesn’t influence the Pd behaviour, whereas in presence of 10 ppm of SO2 some deactivation occurs that becomes more evident above 450 °C at which the catalyst doesn’t reach 100% of meth…
A genetic link between synsedimentary tectonics-expelled fluids, microbial sulfate reduction and cone-in-cone structures
2018
14 pages; International audience; The late Jurassic (Tithonian) marlstones of the Boulonnais area (English Channel, France) contains diagenetic carbonate beds and nodules. Some nodules exhibit cone-in-cone structures on their lower face. We studied such nodules using various techniques of imaging and chemical (major and trace-elements) and isotopic analyses (Ccarb, Corg, O and S stable isotopes). We interpret the cone-in-cone to be the end product of carbonate-nodule formation during early diagenesis. The diagenetic carbonate precipitation was induced by microbial activity (bacteria and(?) archeae) fueled by upward-migrating fluids. Fluid expulsion was itself triggered by synsedimentary fau…
Modulation of induced reversion frequency by nucleotide pool imbalance as a tool for mutant characterization.
1987
Addition of thymidine (TdR) or deoxycytidine (CdR) to the culture medium during posttreatment incubation affected the frequency of mutagen-induced reversion in three hypoxanthine-guanine phosphoribosyl transferase-deficient mutants of V79 Chinese hamster cells. With two of the mutants (E20 and I3), reversions induced by N-ethylnitrosourea, ethyl methanesulfonate, and methyl methanesulfonate were enhanced by TdR and were either decreased (E20) or not affected (I3) by CdR. With the third mutant (E21), alkylating agent-induced reversions were enhanced by CdR and decreased by TdR. Finally, 6-amino-2-hydroxypurine induced reversions were enhanced by TdR in mutant I3 and were decreased by TdR or …
Active Molybdenum‐Based Anode for Dehydrogenative Coupling Reactions
2018
A new and powerful active anode system that can be operated in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been discovered. In HFIP the molybdenum anode forms a compact, conductive, and electroactive layer of higher-valent molybdenum species. This system can replace powerful but stoichiometrically required MoV reagents for the dehydrogenative coupling of aryls. This electrolytic reaction is more sustainable and allows the conversion of a broad scope of activated arenes.