Manufacture of catalysts of the iron molybdate type for use particularly in the catalytic oxidation of alcohols to aldehydes

Claim 1

A process for manufacturing a catalyst consisting essentially of molybdenum and iron in the form of oxides and having an Mo/Fe atomic ratio of about 1.5:1 to 4:1, respectively, comprising the steps of reacting a solution of a molybdenum salt containing molybdenum in an anionic form with a solution of an iron salt containing iron in the form of a ferric cation so as to obtain a precipitate of ferric molybdate; separating the precipitate from the solution; admixing said precipitate with a thermally decomposable acid or neutral ammonium salt of the formula NH4A wherein A is an anion, in an amount of more than 0.3 gram-mole of ammonium salt per gram - equivalent of ferric ion; drying the resultant mixture containing said amount of said ammonium salt at a temperature between 40* and 150*C and, in a fourth stage, heating the resultant dried mixture containing said amount of said ammonium salt to a temperature between 300* and 500*C to thermally decompose same and form said catalyst, whereby said catalyst has a lower specific surface and specific gravity than the same catalyst produced under the same conditions but without the admixture of said ammonium salt.