| abstract |
The present invention is a chromium-free catalyst for the hydrogenation of C 4 dicarboxylic acids and / or derivatives thereof, preferably maleic anhydride in the gas phase, in the form of shaped catalyst bodies containing a mixture of 5 to 95 wt .-% Cu oxide and 5 bis 95 wt .-% of an oxide having acidic centers, characterized in that the volume of the individual molding is less than 20 mm 3 , and a process for the preparation of mixtures of optionally alkyl-substituted GBL and THF in the ratio 0: 1 to 9: 1 by hydrogenation of C 4 dicarboxylic acids and / or their derivatives in the presence of such a catalyst, in which the ratio of the products THF and GBL is adjusted to one another only by varying the temperature in the reactor. |