| abstract |
Hydrogenation catalysts, which have a specific surface area of from 50 to 150 square meters per gram, solely or partially contain crystals having a spinel structure and copper in the form of copper oxide, and have been obtained by precipitating copper and aluminum in a ratio of from 0.25 to 3 atoms of copper per atom of aluminum from their compounds in the presence of a carbonate at a pH of from 4.5 to 9 and calcining the resulting precipitate at from 300° to 800° C., for the catalytic preparation of propanediols by hydrogenating hydroxypropionaldehydes at not more than 300 bar pressure and from 50° to 200° C., and processes for the preparation of propanediols by the use of such catalysts. n The propanediols obtainable by the process of the invention, in particular 2,2-dimethylpropane-1,3-diol, are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example corresponding polyesters. |