摘要:
The invention relates to a process for producing ethane comprising contacting methane with a metal catalyst selected from metal hydrides, metal organic compounds and mixtures thereof. It also relates to a process for the conversion of methane to carbon-containing products comprising contacting methane with a metal catalyst comprising at least one metal, Me, chosen from the lanthanides, the actinides and the metals from Groups 2 to 12 of the Periodic Table of the Elements, so as to produce ethane in a proportion of at least 65%, especially at least 98% or 99% by weight with respect to carbon-containing products formed in the process. The process can be a single-step process, preferably carried out under conditions involving a non-oxidative catalytic coupling of methane, in particular under operating conditions maintained substantially constant, preferably continuously, during the ethane production, e.g. at a temperature ranging from - 30°C to +80°C, preferably from 20°C to 500°C, under a total absolute pressure ranging from 10 -3 to 100 MPa, preferably from 0.1 to 50 MPa. The metal catalyst may be chosen from metal catalysts supported on and preferably grafted to a solid support. One of the main advantages of the present invention is to produce ethane with a very high selectivity.
摘要:
The present invention relates to materials and particularly 'organometallic-organic- inorganic hybrid materials' that can be used as heterogeneous catalysts for selective catalytic reactions. More precisely this invention relates to organic-inorganic hybrid nanostructured materials comprising a regularly distributed stabilized carbene that binds strongly to a metal so as to form a stable organometallic-organic-inorganic hybrid material having high catalytic performances.
摘要:
The present invention relates to a process for the manufacture of alkanes comprising an operation in which at least one starting alkane is contacted with a metal catalyst comprising at least one metal, Me, bonded to at least one hydrogen atom and/or to at least one hydrocarbon radical, characterized in that the catalyst is contacted with an agent which forms hydrogen "in situ" , during the manufacture of alkanes. The present invention also relates to a process for the activation of a metal catalyst intended to manufacture alkanes and comprising at least one metal, Me, bonded to at least one hydrogen atom and/or to at least one hydrocarbon radical, which process is characterized in that, during the manufacture of alkanes carried out by contacting the catalyst with at least one starting alkane, the catalyst is contacted with an agent which forms hydrogen "in situ" . The agent can be chosen from agents capable of releasing hydrogen, preferably by a physical action, and from agents capable of forming hydrogen by a chemical reaction, in particular in the presence of the metal catalyst. The metal Me of the catalyst can be chosen from the lanthanides, the actinides and the metals from Groups 2 to 12, preferably the transition metals from Groups 3 to 11 of the Periodic Table of the Elements. The metal catalyst can be preferably chosen from metal catalysts supported on and in particular grafted to a solid support.
摘要:
Non aqueous solvents or mixtures for DNP NMR spectroscopy, method to prepare said solvents or mixtures and use of said solvents or mixtures The present invention concerns a method to determine the efficiency of a solvent to impregnate a sample material for use in a dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiments, characterized in that the method comprising: - selecting a non-aqueous solvent, - providing a polarizing agent that is soluble in the non-aqueous solvent, - dissolving the polarizing agent in the non-aqueous solvent, - impregnating or dissolving the sample material with the non- aqueous solvent containing the polarizing agent, - performing a solid state DNP NMR experiment on the impregnated sample material, - determining a DNP enhancement factor of the DNP NMR experiment.
摘要:
The invention relates to a supported metal compound, comprising a support made from aluminium oxide to which a tungsten hydride is grafted. The support may be selected from the homogeneous supports with a composition based on aluminum oxide and from heterogeneous supports made from aluminium oxide with aluminum oxide essentially on the surface of said support. The support may in particular comprise aluminium oxide, mixed aluminium oxides and modified aluminium oxides particularly comprising one or more elements of groups 15 to 17 of the periodic table of the elements, such as phosphorus, sulphur, fluorine or chlorine. A support made from porous, non-porous or mesoporous aluminas is preferred. The degree of oxidation of the tungsten may have a value of from 2 to 6. The tungsten atom is generally bonded to one or several hydrogen atoms and optionally to one or several hydrocarbon groups. According to the invention, the compound may be prepared by a dispersion step and grafting of a tungsten organometallic precursor to the support made from aluminium oxide then hydrogenation of the resulting product. The product may be used as catalyst in reactions of cleavage and recombination of hydrocarbons, particularly in hydrocarbon metathesis reactions most particularly of alkanes. The product has a surprising, extremely high catalytic activity in this type of reaction and in particular, a high selectivity for the formation of n-alkanes with relation to iso-alkanes.
摘要:
The present invention relates to a process for the manufacture of alkanes comprising a catalytic reaction resulting from contacting methane with at least one other starting alkane (I) in the presence of a metal compound (C) capable of catalysing a reaction for the splitting and/or recombination of a carbon-carbon bond and/or of a carbon-hydrogen bond and/or of a carbon-metal bond, which catalytic reaction results in the formation of at least one final alkane (II) having a number of carbon atoms equal to or greater than (2). In the process, the contacting operation is carried out under a methane partial pressure equal to or greater than 0.1 MPa, preferably in the range from 0.1 to 100 MPa. The metal compound (C) can be chosen from metal compounds supported on and dispersed over a solid support, metal compounds supported on and grafted to a solid support and non-supported metal compounds. Under these conditions, it was found that the yield of the catalytic reaction was improved, and that the catalytic stability and activity of the metal compound (C) over timer were greatly enhanced.
摘要:
La présente invention concerne un procédé de tranformation de l'éthylène en propylène, dans lequel on fait réagir l'éthylène avec un composé métallique supporté comprenant un support à base d'oxyde d'aluminium sur lequel est greffé un hydrure de tungstène. La réaction peut être conduite entre 20 et 600 °C, de préférence entre 50 et 350 °C, sous une pression absolue comprise entre 0,01 et 8 MPa, de préférence 0,01 et 1 MPa. Le catalyseur peut être régénéré par admission d'hydrogène, à une température comprise entre 50 et 300 °C.
摘要:
La présente invention concerne un composé métallique supporté comprenant un support à base d'oxyde d'aluminium sur lequel est greffé un hydrure de tungstène. Le support peut être choisi parmi les supports homogènes en composition à base d'oxyde d'aluminium et parmi les supports hétérogènes à base d'oxyde d'aluminium comprenant de l'oxyde d'aluminium essentiellement en surface desdits supports. Le support peut en particulier comprendre de l'oxyde d'aluminium, des oxydes mixtes d'aluminium et des oxydes d'aluminium modifiés, comprenant notamment un ou plusieurs éléments des Groupes 15 à 17, tels que le phosphore, le soufre, le fluor ou le chlore, du Tableau de la Classification Périodique des Eléments. On préfère un support comprenant des alumines poreuses, non-poreuses ou mésoporeuses. Le degré d'oxydation du tungstène peut avoir une valeur allant de 2 à 6. L'atome de tungstène est généralement lié à un ou plusieurs atomes d'hydrogène et éventuellement à un ou plusieurs radicaux hydrocarbonés. Le composé selon l'invention peut être préparé par une étape de dispersion et de greffage d'un précurseur organométallique de tungstène sur le support à base d'oxyde d'aluminium, puis par hydrogénolyse du produit résultant. Le composé selon l'invention peut être utilisé comme catalyseur dans des réactions de scission et recombinaison d'hydrocarbure(s), notamment dans des réactions de métathèse d'hydrocarbure(s), notamment d'alcane(s). Il présente d'une façon surprenante une activité catalytique extrêmement élevée dans ce type de réaction, et notamment une sélectivité élevée dans la formation des n-alcanes par rapport à celle des iso-alcanes.
摘要:
The present invention relates to a supported metal compound comprising a solid support to which are grafted at least two types of metal atom, Me, one in a form (A) of a metal compound where the metal atom is bonded to at least one hydrogen atom and/or to at least one hydrocarbon, and the other in a form (B) of a metal compound where the metal atom is bonded solely to the support and optionally to at least one other element which is neither a hydrogen atom nor a hydrocarbon radical. The compound can be prepared (a) by grafting an organometallic precursor (P) comprising the metal Me, bonded to at least one hydrocarbon ligand, to the solid support, and (b) by treating the solid product resulting from step (a) with hydrogen or a reducing agent, at a temperature greater than the temperature, TI, at which the supported metal compound is formed solely in the form (A), and at a temperature lower than the temperature, T2, at which the supported metal compound is formed solely in the form (B). The compound can be used in particular as a catalyst in a process employing hydrocarbon splitting and recombination reactions, e.g. in a hydrocarbon metathesis reaction, with a greatly increased catalytic activity, in comparison with a supported metal compound which is identical but which would include only the form (A), the form (B) being inactive in this type of reaction.
摘要:
ABREGE DESCRIPTIF Procédé de métathèse de composés comportant une double liaison oléfinique, notamment d'oléfines La présente invention concerne un procédé de métathèse d'un ou plusieurs réactifs comportant une chaîne hydrocarbonée linéaire ou ramifiée comportant une double liaison oléfinique Csp 2 = Csp 2 , dans lequel on fait réagir ce ou ces réactifs avec un composé métallique supporté comprenant un support à base d'oxyde d'aluminium sur lequel est greffé un hydrure de tungstène. Typiquement, le ou les réactifs comportent chacun de 2 à 30 atomes de carbone. Le réactif peut être notamment une oléfine. Par exemple le procédé produit du propylène à partir d'éthylène et de butène.