A honeycomb catalyst consisting of from 30 to 95% by weight, calculated as Fe.sub.2 O.sub.3, of an iron compound and from 0.1 to 60% by weight, calculated as Al.sub.2 O.sub.3, CeO.sub.2 or Cr.sub.2 O.sub.3, of an aluminum, cerium and/or chromium compound and/or from 1 to 50% by weight of an alkali metal compound, in particular potassium, calculated as K.sub.2 O, and/or from 0.2 to 20% by weight, calculated as MeO.sub.3, of an element of sub-group 6, preferably MoO.sub.3 and WO.sub.3, and/or from 0.1 to 20% by weight, calculated as V.sub.2 O.sub.5, of a compound of vanadium and/or from 0.1 to 20% by weight, calculated as P.sub.2 O.sub.5, of a compound of phosphorus, a process for the preparation of the honeycomb catalyst, and the use of the catalyst for organic reactions.