Propylene Oxidation to Acrolein over Cu/MoO3 Nanobelt Composites

Abstract Nanocomposites comprised of MoO 3 nanobelts with Cu 6 Mo 5 O 18 derived surface layers are very active for propylene oxidation to acrolein with selectivity approaching 60% between 350–400 °C. They offer high surface areas (∼18 m 2 g −1 ) and yield acrolein formation rates exceeding those of unpromoted bismuth molybdates which are the basis of industrial catalysts. Their acrolein selectivity is also markedly higher than that of the Cu 2+ molybdates α‐CuMoO 4 and Cu 3 Mo 2 O 9 . XPS and TPR analyses point to the formation of a Cu + containing molybdate on the MoO 3 nanobelt surfaces which is identified as Cu 6 Mo 5 O 18 by its unique Raman bands. Kinetic analyses suggest that this surface layer facilitates catalyst re‐oxidation which remains the rate‐determining step of acrolein formation over the nanocomposites up to 400 °C. Thus, the nanocomposites present a very efficient copper molybdate catalyst design for propylene oxidation to acrolein which is also less susceptible to carbon induced deactivation than bulk Cu 2+ molybdates.