The invention provides a process for preparing olefins from a mixed gaseous feed stream, wherein said mixed gaseous feed stream comprises three or more components selected from the group consisting of carbon dioxide, carbon monoxide, hydrogen, methanol and dimethyl ether, said process comprising contacting the mixed gaseous feed stream with a catalyst of formula (I): Μ(ΙΙ)χΑl11-χΡO4 (I), wherein M(II) is a divalent metal ion; and x = 0.002 to 0.5</p
