GB902368A - Oxidation of alcohols - Google Patents

Abstract

A catalyst for oxidizing alcohols to carbonyl compounds at a pH below 4 comprises a halogen-containing compound of platinum, palladium, or rhodium. The metal is present or is brought to the higher valency form in which it can exist. The catalyst may be supported and may include an acid compound, e.g. hydrochloric acid, sulphuric acid, phosphoric acid, trifluoroacetic acid, alkyl or aryl sulphonic acids, halogen-substituted alkyl or aryl sulphonic acids or boron fluoride complexes. When a non-halogen acid is added halogens may be added to the catalyst in the form of salts, e.g. ammonium, manganese or cupric chloride. There may also be present compounds or ions of Group I, II, V, VI and VII metals, e.g. copper, silver, mercury, vanadium, chromium or manganese. The catalyst may be regenerated by treatment with oxygen. An activator may be present in the reaction or regeneration zone. Suitable activators are, for example, hydrogen bromide, ozone, t-butyl peroxide, benzoyl peroxide, cumene hydro-peroxide, cumene, iodine, nitric oxide, quinone, aldehydes and isobutyro-azo-dinitrile.ALSO:Carbonyl compounds are produced by intimately contacting a feed comprising a C2 to C8 saturated alcohol in the liquid phase and at a pH below 4 with a catalyst comprising a halogen-containing compound of platinum, palladium or rhodium at a temperature in the range 50-300 DEG C., and recovering a saturated carbonyl compound having the same number of carbon atoms as the alcohol. The metal is present in the higher valency form in which it exists. The alcohol used as feed may be formed in situ from the corresponding olefine. The preferred catalyst is chlorplatinic acid. The catalysts may include an acid compound, e.g. hydrochloric acid, sulphuric acid, phosphoric acid, trifluoroacetic acid, alkyl or aryl sulphonic acid, halogen substituted alkyl or aryl sulphonic acids or boron fluoride complexes. When a non-halogen acid is used halogens may be added in the form of salts, e.g. ammonium, manganese or cupric chloride. There may also be present compounds or ions of Group I, II, V, VI and VII metals e.g. copper, silver, mercury, vanadium, chromium or manganese. The catalyst may be used on a support. An organic solvent, e.g. benzene, toluene, xylene, tetrahydrofuran, biphenyl, chlorobenzene, dichlorobenzene and alcohols such as C8-C20 alcohols or neopentyl alcohol, may be used. If desired, oxygen may be passed into the reaction mixture and the catalyst may be regenerated by treatment with oxygen. Chelating agents or catalyst activators may also be added to the mixture in the reaction zone or activators may be added to the catalyst in the regenerating zone.