Preparation of dpa over fluoride impregnated catalyst

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF DIPHENYLAMINE FROM ANILINE WHEREIN ANILINE VAPOR UNDR SUPERATMOSPHERIC PRESSURE IS CONTACTED WITH AN ALUMINA CATALYST AT A TEMPERATURE ABOVE 400*C., WHEREBY AN EFFLUENT VAPOR MIXTURE, CONTAINING PRODUCT DIPHENYLAMINE IS OBTAINED, THE IMPROVEMENT WHICH COMPRISES USING AS SAID CATALYST AN ACTIVATED ALUMINA PREPARED BY A PROCESS WHICH COMPRISES CONTACTING SAID ALUMINA IN PARTICULATE FORM WITH AN AQUEOUS SOLUTION CONTAINING A CONCENTRATION OF FROM ABOUT 0.5 TO ABOUT 10 WEIGHT PERCENT OF A WATER SOLUBLE INORGANIC FLUORIDE, SEPARATING SO-TREATED PARTICULATE ALUMINA FROM RESIDUAL AQUEOUS SOLUTION AND DRYING THE SOSEPARATED IMPREGNATED PARTICLES, SAID FLUORIDE BEING SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL, AMMONIUM AND HYDROGEN FLUORIDES.