Novel Mo-V Oxide Catalysts with Nanospheres as Templates for the Selective Oxidation of Acrolein to Acrylic Acid

Abstract

Novel Mo-V-PMMA and Mo-V-PS catalysts are prepared by addition of hard polymethyl methacrylate (PMMA) and polystyrene (PS) nanospheres into Mo/V compounds in the preparation process, respectively. The catalytic tests in selective oxidation of acrolein reveal that Mo-V-PMMA catalyst shows very high acrolein conversion (99.1%) and the yield of acrylic acid (90.7%). The BET, DLS, SAXS, XRD, XPS, H2-TPR and NH3-TPD measurements reveal that the addition of PMMA and PS nanospheres causes the obvious changes of porous structure, crystal phases composition and chemical properties of catalysts. These differences between Mo-V-PMMA and Mo-V-PS catalysts are attributed to the totally different “real” nano–environment during heat treatment in the high–concentration component mixture. PS nanospheres are in a state of adhesion or agglomeration or not uniformly distributed in the active component solution, while PMMA nanospheres with much better hydrophilicity and monodispersed state promote Mo and V ions more easily and uniformly dispersed in the mixture. Novel Mo-V catalysts are prepared by addition of hard polymethyl methacrylate (PMMA) and polystyrene (PS) nanospheres into Mo/V mixture. Obvious changes of porous structure, crystal phases and chemical properties of catalysts are caused by the nanospheres introduction, showing very high acrolein conversion (99.1%) and the yield of acrylic acid (90.7%) in selective oxidation of acrolein.