Structure-catalytic efficiency relationships in USb oxide acrylonitrile synthesis catalysts

A novel uranium-antimony oxide catalyst which has recently entered full-scale commercial production and use is shown to be highly effective for the direct oxidation of propylene-ammonia to acrylonitrile. Direct single-step conversion of propylene feed to acrylonitrile in excess of 80% was achieved in a laboratory-scale fluidized-bed reactor. Approximately 6% of the propylene is converted to HCN, less than 1% to acetonitrile, and only traces to condensable oxygenated organics. The interdependence of catalytic efficiency, catalyst crystalline structure, low-frequency infrared spectral characteristics, electron spin resonance behavior, and catalyst composition is discussed. Antimony-uranium containing crystalline phases were identified and correlated to effectiveness in acrylonitrile synthesis.