Promotional effect of cerium on Mo–V–Te–Nb mixed oxide catalyst for ammoxidation of propane to acrylonitrile

• Adding Ce in Mo-V-Te-Nb-O(M) can improve its catalytic activity for C3H6 ammoxidation.
• MCex catalyst with Ce/Mo = 0.05 exhibits the best catalytic performance.
• Adding Ce helps to form more M1 & M2 active phases and higher surface Ti4+ density.
• Presence of Ce3+/Ce4+ redox pairs promote redox capability of the MCex catalyst.

The MoV0.31Te0.23Nb0.24 mixed oxide (M) catalysts with different cerium amounts for propane ammoxidation to acrylonitrile were synthesized by the co-precipitation method. The effect of cerium content on the physicochemical property of the M catalyst was investigated by low-temperature N2 adsorption, XRD, XPS and H2-TPR. The results show that the presence of cerium in the M catalyst can significantly enhance its catalytic performance for propane ammoxidation. 46% acrylonitrile yield can be obtained over the MCe0.05 catalyst with Ce/Mo = 0.05 (mol) at SV of 1200 mL/(h.g), in which there are most optimal surface compositions, such as more M1 and M2 active phases, and higher Te4 + concentration and appropriate V content. The presence of Ce3 +/Ce4 + pairs promotes the redox capability of the M catalyst and more reasonable atom distribution on the catalyst surface.