Bismuth molybdate based catalyst

The invention concerns a method for producing a multiphase mixed-oxide catalyst comprising at least one active phase based on bismuth molybdate and one co-catalyst based on iron molybdate and at least one amongst the two elements cobalt and nickel, said method comprising the following steps: preparing a mixture of the precursors of said mixed oxides in a solvent, making said precursors react through a microwave-assisted hydrothermal reaction, and isolating the mixed oxides to obtain the catalyst. A catalyst and a catalytic system prepared in this manner are part of the invention as well as the uses of this catalyst and of this catalytic system, in particular in the oxidation of propene into acrolein.