Supported catalyst - for acrylic acid prodn contg oxides of nickel, cobalt, iron, phosphorus, potassium and molybdenum

摘要

Supported catalyst contg. the active elements in the atomic ratio Ni3-12Co0-12Fe0.5-10Bi0.5-10, PO, 1-6K0.001-2Mo12O37-118 the indices for Ni and Co being not simultaneously zero, on a solid support with a particle size of 0.01-5mm is prepd. by (a) applying to the support an aqs. soln. of ammonium heptamolybdate and phosphoric acid in =1 impregnation stages, the volume of soln. applied being 1-2 times the predetermined pore volume of the support, (b) drying for 3-10 hrs. at 100-300 degrees C after each impregnation, (c) applying to the support an aqs. nitric acid soln, iron, bismuth, potassium and nickel and/or cobalt niraes in =1 impregnation stages, the volume of soln. applied being 1-2 times the predetermined pore volume of the support, (d) maintaning for 2-12 hrs. at 70-95 degrees C after each impregnation, (e) drying for 3-10 hs. at 100-300 degrees C and (f) sintering for 0.5-10 hrs. at 400-700 degrees C so that the catalyst has a BET surface of 5-100 m2/g. Used for prepn. of acrylic acid by the one stage oxidn. of propylene and/or acrolein with oxygen in the gas phase. High yields and conversions are obtained without the need for recycling unconverted reactants, by products and inert gases.