Method for making supported silver catalysts

Claim 1

IN THE PROCESS FOR THE PRODUCTION OF A SILVER CATALYST COMPOSITION WHEREIN AQUEOUS SILVER NITRATE IS COMBINED WITH AN INERT POROUS SOLID SUPPORT IN A TOTAL AMOUNT WHICH UPON REDUCTION PROVIDES A CONECENTRATION OF FROM ABOUT 2 TO ABOUT 15% BY WEIGHT OF METALLIC SILVVER IN SAID CATALYST COMPOSITION, AND SAID SILVER NITRATE IS REDUCED TO METALLIC SILVE ON SAID SUPPORT, THE STEPS WHICH COMPRISE COMBINING WITH SAID SUPORT ONLY A FRACTION OF SAID TOTAL AMOUNT OF SAID AQUEOUS SILVER NITRATE, REDUCING SAID SILVER NITRATE COMBINED WITH SAID SUPPORT TO METELLIC SILVER BY HEATING AT A TEMPERATURE OF FROM ABOUT 150 TO ABOUT 400* C. IN A REDUCING ATMOSPHERE, COMBINING THE RESULTING SILVER METALCONTAINING COMPOSITION WITH THE REMAINDER OF SAID TOTAL AMOUNT OF SAID AQUEOUS SILVER NITRATE, AND REDUCING SAID SILVER NITRATE ADDITIONALLY COMBINED WITH SAID SILVER METALCONTAINING SUPPORT TO METALLIC SILVE BY AGAIN HEATING AT A TEMPERATURE OF FROM ABOUT 150 TO ABOUT 400* C. IN A REDUCING ATMOSPHERE, THEREBY OBTAINING A SILVER CATALYST CONTAINING FROM 2 TO 15% METALLIC SILVER HAVING A GREATER ACTIVITY FOR THE ETHYLENE OXIDATION REACTION THAN A SIMILAR CATALYST CONTAINING THE SAME AMOUNT OF SILVER PREPARED BY REDUCING SILVER NITRATE UPON THE SUPPORT BUT IN THE ABSENCE OF A REDUCTION OF A PART OF THE SILVER NITRATE TO ELEMENTAL SILVER BEFORE A SUBSEQUENT IMPREGNATION WITH A FURTHER AMOUNT OF SILVER NITRATE.