| abstract |
Aldehydes and ketones of the general formula I ##STR1## where R 1 is hydrogen or an organic radical of 1 to n carbon atoms and R 2 is a non-aromatic organic radical of 1 to m carbon atoms, (m+n) ranging from 2 to 24 and R 1 and R 2 being combinable to form a 4- to 12-membered ring, are prepared in a continuous manner by oxidizing an alcohol of the general formula II ##STR2## with oxygen or an oxygen-containing gas at elevated temperatures in the gas phase in the presence of a catalyst, by effecting the oxidation by means of a supported catalyst composed of an inert carrier having a smooth surface and from 0.1 to 20% by weight, based on the amount of carrier, of an active layer of copper, silver and/or gold in a tubular reactor or tube bundle reactor where the internal diameter D of the tube or tubes ranges from 10 to 50 mm and the largest diameter d of the coated supported catalysts is subject to the relationship d=from 0.1 to 0.2 D. |