摘要:
The invention relates to a supported catalyst and the production and use thereof in the synthesis of vinyl acetate in the gaseous phase from ethylene, acetic acid and oxygen, or from gases containing oxygen, whereby the activity and selectivity are simultaneously improved. The catalyst contains palladium, at least one alkali metal compound and optionally one or more catalyst accelerators, in particular, gold, barium and/or cadmium on a porous support. Said support contains at least one reducible metal oxide, in particular oxides of the elements of groups IIIb, IVb, Vb, VIb from the periodic table of elements. Once the support has been loaded with at least one palladium compound, a reduction is carried out at a temperature of >200° C.
摘要:
Supported catalysts having a high sintering stability and comprising one or more noble metal cluster carbonyl compounds of the formula (1) [HaMbNcLd(CO)x]n−An+ and their use for the dehydrogenation, hydrogenation and oxidation of organic compounds where M and N are, independently of one another, one or more metals selected from the group consisting of Pt, Rh, Ir, Os, Ru, Ag, Pd, Au, Ni, Fe, Co, Cu, Re, Mn; L is one or more neutral or anionic ligands which may be identical or different; (A)n+ is one or more cations which balance the charge of the complex; a is an integer from 0 to 10, preferably from 0 to 6; b is an integer from 2 to 60; c is an integer from 0 to 30; d is an integer from 0 to 60; x is an integer from 1 to 120; n is the total charge of the complex which results from the individual charges of the constituents and is greater than 0, wherein the compounds of the formula (1) are located in the pores of a mesoporous support material.
摘要:
A process for preparing a bicyclooctanone, in particular 1,5-dialkylbicyclo[3.2.1]octan-8-one, by reacting a bicyclooctanol, in particular dialkylbicyclo[3.2.1]octan-8-ol, with a. a catalyst applied to an active-carbon support and comprising heteropolyoxometallate anions of vanadium, molybdenum and phosphorus, and also a corresponding alkali-metal, alkaline-earth-metal and/or ammonium counter ion, and b. a gaseous, oxygen-containing oxidizing agent.
摘要:
The invention relates to a process for producing supported shell catalysts comprising noble metals by UV photoreduction of noble metal salt precursors fixed to a support. For this purpose, the shaped supported body is impregnated with suitable noble metal salts which are then reduced to the metals in a zone close to the surface by means of UV radiation, preferably in the absence of a chemical reducing agent. The metal salts in the interior of the pellets which have not been irradiated and therefore have not been reduced are extracted using a solvent. The noble metal shell catalysts produced in this way can be used for many heterogeneously catalyzed reactions such as hydrogenations and oxidations. According to the invention, Pd/Au shell catalysts on porous ceramic supports, e.g. SiO2 shaped bodies, produced by this process can be used in the synthesis of vinyl acetate.