Abstract: Catalysts of oxidizing acrolein to acrylic acid were developed by Lanzhou Petrochemical Research Center and applied in some industrial units. However, with the prolongation of operation period the yield of acrylic acid was gradually reduced. In order to investigate the main causes of catalyst deactivation, the physical-chemical properties of fresh catalyst and catalyst used for 2.5-year were compared using XRD, X-fluorescence, TGA and other techniques. Results showed that the loss of main active components, Mo and V, and co-components, Cu and Sr, was one of the main causes for catalyst deactivation. Besides, the phase transition of Sb+3Sb+5O4 to Sb2O3 might also have negative effect on catalyst activity. However, the yield of acrylic acid could be increased after used catalyst regeneration.

Key words: Propylene, Acrolein, Acrylic Acid, Catalyst, deactivation