| 摘要 |
<p>The invention relates to the preparation of a benzaldehyde by hydrogenation of a corresponding benzoic acid in the gas phase in the presence of a manganese containing catalyst on an acid carrier. The invention is characterized in that use is made of a catalyst prepared by a) coprecipitation, at a pH between 7 and 10, of a manganese salt and a salt from which an acid carrier is formed, b) subsequent calcination at a temperature between 300 and 700 &loz& C, c) followed by reduction with a hydrogen containing gas mixture. Preferably the catalyst contains oxides of aluminium, zirconium, titanium, hafnium and/or niobium.</p> |
