Method of preparing catalysts

Claim 1

IN THE PROCESS OF PREPARING A CATALYST CONSISTING ESSENTIALLY OF CHROMIA DEPOSITED ON GRANULAR POROUS ALUMINA, THE IMPROVEMENT WHICH COMPRISES PARTIALLY FILLING THE PORES OF GRANULES OF ALUMINA WITH A SUBSTANTIALLY COMPLETELY VOLATIZABLE LIQUID CHEMICALLY UNREACTIVE THEREWITH, CONTACTING SAID PARTIALLY FILLED GRANULES OF ALUMINA WITH A SOLUTION OF A CHROMIUM COMPOUND DECOMPOSABLE TO CHROMIA, MAINTAINING SAID PARTIALLY FILLED GRANULES OF ALUMINA IN CONTACT WITH SAID SOLUTION FOR A PERIOD OR TIME SUFFIECIENT TO PERMIT SAID SOLUTION TO PENETRATE INTO THE PORES OF THE ALUMINA TO A DEPT SUFFICIENT TO PLACE A CATALYTIC AMOUNTS TO CHROMIA WITHIN SAID PORES, REMOVING THE GRANULES OF ALUMINA SO TREATED FROM CONTACT WITH SAID SOLUTION BEFORE APPRECIABLE DIFFUSION THEREOF INTO THE PORES OCCUPIED BY SAID LIQUID ENSUES, THEREAFTER DRYING THE RESULTING PRODUCT TO REMOVE SUBSTANTIALLY ALL OF SAID VOLATIZABLE LIQUID AND THE SOLVENT OF SAID SOLUTION TO YIELD A GRANULAR CATALYST HAVING A CORE COMPOSED OF ALUMINA AND A SHELL OVERLYING SAID CORE COMPOSED OF ALUMINA IMPREGNATED WITH A CATALYST AMOUNT OF CHROMIA.