Applied Catalysis, 25 (1986) 335-344 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands Fe-Se-TELLURATES AS AMMOXIDATION CATALYSTS Robert K. Grasselli, James F. Brazdil, and James D. Burrington Sohio Research, 4440 Warrensvi I le Center Road,Cleveland, Ohio 44128, U.S.A. ABSTRACT Acrylonitrile is a versatile intermediate and is produced by the Sohio ammoxidation process world-wide at a level of 8 billion pounds per year. In the catalytic process, propy lene, ammonia and air are converted to acrylonitri le directly. The most widely used catalysts are mixed metal molybdates or antimonates. The current investigation deals with metal tellurates as possible low temperature ammoxidation catalysts. Of the catalysts investigated, iron- selenium-tel lurates are of particular interest ammoxidation activity already at 320°C which since they exhibit good is about 100°C lower than the temperature required for molybdate or antimonate systems. Mechanistically, the tellurates behave more similarly to the antimonates than the molybdates. INTRODUCTION Eighty-five percent of industrial organic chemicals are produced from petroleum and natural gas sources. About one-quarter of these chemicals are produced by selective oxidation or ammoxidation processes. An important component of this technology is the Sohio ammoxidation process for the catalytic conversion of propylene, ammon i a, and air to acrylonitrile, a useful intermediate for the production of synthetic fibers, rubbers, and many specialty materials. The Sohio-discovered ammoxidation process displaced the more expensive acetylene-HCN based. route and resulted in a substantial ly lower price and dramatically higher production of this versati le monomer’. Currently, virtually all of the 8 billion pounds of acrylonitrile produced annually world-wide are manufactured by the Sohio p races s . The process uses catalysts comprised of complex mixed metal molybdates or antimonates 2,3 . In addition to the molybdates and antimonates, oxidation and ammoxidation catalysts containing tellurium and selenium are also known 4-10 . This contribution describes the mechanistic and solid state aspects of metal tellurates as ammoxidation catalysts. Among the systems studied, zyxwvutsrqponmlk 0166-9834/86/$03.50 0 1986 Elsevier Science Publishers B.V.