Process for preparing unsaturated nitriles

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ACRYLONITRILE AND METHACRYLONITRILE BY REACTING A GAS SELECTED FROM THE GROUP CONSISTING OF PROPYLENE AND ISOBUTYLENE, RESPECTIVELY, WITH AMMONIA AND A MEMBER SELECTED FROM THE GROUP CONSISTING OF AIR AND OXYGEN AT ABOUT 300* TO 465* C. UNDER A PRESSURE OF ABOUT 0.3 TO 10 ABSOLUTE ATMOSPHERES ON A CATALYST APPLIED TO A CARRIER SELECTED FROM THE GROUP CONSISTING OF SILICICI ACID, PULVERIZED PUMICE, KIESELGUHR, ALUMINUM OXIDE AND MIXTURES THEREOF, AND WITH A TIME OF STAY OF THE GAS MIXTURE ON THE CATALYST BETWEEN 0.2 TO 50 SECONDS, THE IMPROVEMENT WHEREIN SAID CATALYST CONSISTS OF MO03 AND P2O5 AND AN OXIDE SELECTED FROM THE GROUP CONSISTING OF FE203 AND NIO AND MIXTURES THEREOF, IN THE FORM OF GRAINS HAVING A DIAMETER OF ABOUT 0.01 TO 1.0 MILLIMETER, THE GAS MIXTURE CONTAINING 1.5 TO 2.5 MOLS OF OXYGEN, 1.0 TO 1.5 MOLS OF AMMONIA AND 0 TO 20 MOLS OF WATER IN THE FORM OF STEAM PER MOL OF PROPYLENE AND ISOBUTYLENE RESPECTIVELY.