Catalyst for oxidation of ethylene to ethylene oxide

Claim 1

A CATALYST COMPOSITION FOR THE OXIDATION OF ETHYLENE TO ETHYLENE OXIDE WHICH COMPRISES SILVER CATALYST AND, AS A MODERATOR, AT LEAST ONE RARE EARTH METAL SELECTED FROM THE GROUP CONSISTING OF PRASEODYMIUM, NEODYMIUM, TERBIUM AND DYSPROSIUM WHICH IS PREPARED BY COATING A CARRIER WITH A SLURRIED SOLUTION WHICH CONTAINS REDUCED SILVER IN THE FORM OF SILVER POWDER AND A SALT OF AT LEAST ONE RARE EARTH METAL SELECTED FROM THE GROUP CONSISTING OF PRASODYMIUM, NEODYMIUM, TERBIUM AND DYSPROSIUM AND DRYING THE COATED CARRIER, WHEREIN SAID REDUCED SILVER IS PREPARED AS SILVER POWDER BY THE CHEMICAL REACTION OF SILVER OXIDE IN AN AQUEOUS SOLUTION, AND WHEREIN THE REDUCED SILVER AND THE SALT OF THE RARE EARTH METAL ARE PREVIOUSLY COMBINED BY IMMERSING THE REDUCED SILVER INTO AN AQUEOUS SOLUTION OF A SOLUBLE SALT OF SAID RARE EARTHMETAL, ADDING THERETO AN AQUEOUS SOLUTION OF ALKAL OR ALKALINE EARTH HYDROXIDE THEREBY CONVERTING SAID SOLUBLE SALT OF SAID RARE EARTH METAL INTO THE INSOLUBLE HYDROXIDE AND PRECIPITATING SAID INSOLUBLE HYDROXIDE ON THE REDUCED SILVER, FILTERING OFF THE COMBINED REDUCED SILVER AND PRECIPITATED RARE EARTH METAL HYDROXIDE, AND WASHIING THEM WITH WATER.