Abstract: Carbon deposition and catalyst deactivation of Sb-Fe oxide catalyst in the ammoxidation of propylenewere investigated by means of a fluidized-bed reactor.The reactivity,surface acidity,specific surfacearea,average pore radius,and electron spin resonance spectrum data were obtained from the catalysts ofincreasing carbon deposition.Chemisorption of oxygen and propylene and thermal programmed desorptionof propylene were carried out on the Sb-Fe oxide catalyst as well as a commercial one,Mo-Bi.Isotopicexperiment using acrylonitrile-2-~(14)C as tracer was also accomplished.It was found that carbon deposition due to intermediates and acrylonitrile on selective oxidation sitescould be the primary reason for catalyst deactivation,and that because of the Sb-Fe oxide catalytspossessing a property of easy reduction and difficult reoxidation,the structure of the FeSbO_4 would bedecomposed under the oxygen-lean condition into Sb_2O_3 and Fe_2O_3 which form the deep oxidation catalystcomponent.According to the above investigation a suggestion for improving catalyst properties has been proposed.

摘要： Carbon deposition and catalyst deactivation of Sb-Fe oxide catalyst in the ammoxidation of propylenewere investigated by means of a fluidized-bed reactor.The reactivity,surface acidity,specific surfacearea,average pore radius,and electron spin resonance spectrum data were obtained from the catalysts ofincreasing carbon deposition.Chemisorption of oxygen and propylene and thermal programmed desorptionof propylene were carried out on the Sb-Fe oxide catalyst as well as a commercial one,Mo-Bi.Isotopicexperiment using acrylonitrile-2-~(14)C as tracer was also accomplished.It was found that carbon deposition due to intermediates and acrylonitrile on selective oxidation sitescould be the primary reason for catalyst deactivation,and that because of the Sb-Fe oxide catalytspossessing a property of easy reduction and difficult reoxidation,the structure of the FeSbO_4 would bedecomposed under the oxygen-lean condition into Sb_2O_3 and Fe_2O_3 which form the deep oxidation catalystcomponent.According to the above investigation a suggestion for improving catalyst properties has been proposed.