摘要:
Process for preparing propene oxide, in which a mixture of propene and oxygen or an oxygen-containing gas is reacted at a temperature in the range from 150 to 500° C., in the presence or absence of a catalyst, in a reactor, wherein all or part of the interior of the reactor is lined with inert materials. The inert material used is at least one of the materials of the following group: one or more noble metals of transition group VIII of the Periodic Table, in particular gold, titanium and tantalum, glass, enamel, quartz, ceramic and Teflon. The selectivity to propene oxide is >60%.
摘要:
A process is disclosed for selectively preparing acetic acid from a gaseous feed of ethane, ethylene or mixtures thereof, as well as oxygen, at an increased temperature, on a catalyst which contains the elements W, X, Y and Z in the gram-atom ratio a:b:c:d, associated with oxygen. In the formula WaXbYcZd (I), X stands for one or several elements selected from the group Pd, Pt, Ag and/or Au; Y stands for one or several elements selected from the group V, Nb, Cr, Mn, Fe, Sn, Sb, Cu, Zn, U, Ni and/or Bi; Z stands for one or several elements selected from the group Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Ti, Zr, Hf, Ru, Os, Co, Rh, Ir, B, Al, Ga, In, Tl, Si, Ge, Pb, P, As and/or Te; a equals 1, b is a number higher than 0, c is a number higher than 0, and d is a number from 0 to 2. Also disclosed is said catalyst.
摘要:
The present invention relates to a process for the selective preparation of acetic acid from a gaseous feed comprising ethane, ethylene or mixtures thereof plus oxygen at elevated temperature, which comprises bringing the gaseous feed into contact with a catalyst comprising the elements Mo, Pd, X and Y in gram atom ratios a:b:c:d in combination with oxygen MoaPdbXcYd (I) where the symbols X and Y have the following meanings: X is one or more elements selected from the group consisting of: Cr, Mn, Nb, Ta, Ti, V, Te and/or W, in particular Nb, V and W; Y is one or more elements selected from the group consisting of: B, Al, Ga, In, Pt, Zn, Cd, Bi, Ce, Co, Cu, Rh, Ir, Au, Ag, Fe, Ru, Os, K, Rb, Cs, Mg, Ca, Sr, Ba, Zr, Hf, Ni, P, Pb, Sb, Si, Sn, TI and U, in particular Ca, Sb, Te and Li. The present invention further provides a catalyst for the selective preparation of acetic acid comprising the elements Mo, Pd, X and Y in the gram atom ratios a:b:c:d in combination with oxygen. The process can be illustrated by the following reaction scheme,
摘要:
Polybetaine-stabilized, palladium-containing nanoparticles, a process for preparing them and also catalysts prepared from them for producing vinyl acetate. The invention relates to soluble nanoparticles which comprise palladium alone or palladium together with metals of the groups 8-11 of the periodic table and which are embedded in protective colloids, wherein the protective colloids comprise at least one polymer having betaine groups, and to a process for preparing them. The soluble nanoparticles are suitable for the preparation of catalysts.
摘要:
A process for the selective preparation of acetic acid from a gaseous feed comprising ethane, ethylene or mixtures thereof plus oxygen at elevated temperature, which comprises bringing the gaseous feed into contact with a catalyst comprising the elements Mo, Pd, Re, X and Y in gram atom ratios a:b:c:d:e in combination with oxygenMo.sub.a Pd.sub.b Re.sub.c X.sub.d Y.sub.e (I)where the symbols X, Y have the following meanings:X=Cr, Mn, Nb, B, Ta, Ti, V and/or WY=Bi, Ce, Co, Cu, Te, Fe, Li, K, Na, Rb, Be, Mg, Ca, Sr, Ba, Ni, P, Pb, Sb, Si, Sn, Tl and/or U;the indices a, b, c, d and e are the gram atom ratios of the corresponding elements, wherea=1, b>0, c>0, d=0.05-2, e=0-3.
摘要:
The invention relates to a method for producing aldehydes and ketones from easily accessible primary and secondary alcohols by oxidation with atmospheric oxygen or pure oxygen using a catalyst system which consists of a derivative of a free nitroxyl radical.
摘要:
The invention relates to a process for enzymatic deracemization of enantiomer mixtures of secondary alcohols by a combination of oxidation and reduction reactions by means of stereoselective alcohol dehydrogenases and the cofactors thereof, wherein one enantiomer of an optically active secondary alcohol is in a formal sense selectively oxidized to the corresponding ketone, which is subsequently reduced selectively to the optical antipode, while the reduced form of the cofactor is provided for the reduction reaction by means of an additional enzyme, characterized in that two alcohol dehydrogenases with opposite stereoselectivity and different cofactor selectivity and the two corresponding, different cofactors are used for the oxidation and reduction reactions, and the oxidized and reduced cofactors are interconverted in a parallel enzymatic reaction with the additional enzyme, the direction of the deracemization toward one of the two enantiomers being controllable by the selection of the two alcohol dehydrogenases or using the selectivity difference of the additional enzyme for the two cofactors.
摘要:
The present invention relates to ligands of the general formula (I). In addition, a process for the production thereof and the use thereof are demonstrated.
摘要:
The present invention relates to novel nitrogen-containing monodentate phosphane ligands of formula (I) and to their use in catalytic reactions, especially in the improvement of haloaromatic compounds.
摘要:
The present invention relates to ligands of the general formula (I). In addition, a process for the production thereof and the use thereof are demonstrated.