STUDIES ON THE TPR CHARACTERISTICS AND OX IDATION ACTIVITIES OF CATALYSTS OF CU,AG AND CU-AG SUPPORTED ON GAMMA-AL2O3

The reducibility of the gamma - Al2O3 supported Cu - Ag bimetallic and the individual mono metallic catalysts and the effect of thermal trea tment on the reducibility of these catalysts have been investigated wi th the temperature - programmed reduction (TPR) technique. It is found that different TPR profiles are produced with different metal content s and different copper species are present on the surface of catalysts . There is obvious difference between the TPR profiles of gamma - Al2O 3 supported Cu - Ag bimetallic and the mono - metallic catalysts and t he displacement increase with the content of Ag. The order of activity of catalyst for benzene oxidation is: CuO - Ag2O/gamma - Al2O3 > CuO/ gamma - Al2O3 > Ag2O/gamma - Al2O3 The results show that the dispersio n of copper species and the reducibility of the catalysts are affected by the variation of treatment temperature. The optimal dispersion of copper species occurs at a temperature between 500 and 900 degrees C.