A process for the manufacture of acrylic acid comprising reacting propylene and oxygen (preferably in the form of air) in a reaction zone having a catalyst characterized by the following formula: AaBbCcCadFeeBifMo12Ox where A=one or more of Li, Na, K, Rb and Cs B=one or more of Mg, Sr, Mn, Ni, Co and Zn C=one or more of Ce, Cr, Al, Sb, P, Ge, Sn, Cu, V and W and a=0.01 to 1.0; b and e =1.0-10 c=0 to 5.0, preferably 0.05 to 5.0, especially preferred being 0.05 to 4.0 d and f=0.05 to 5.0, and x is a number determined by the valence requirements of the other elements present; at an elevated temperature to produce acrylic acid and acrolein.