A COMPARATIVE STUDY OF SILVER – COBALT AND SILVER – MANGANESE COMPOSITE OXIDE CATALYSTS: PREPARATION, CHARACTERIZATION AND TESTING FOR THE OXIDATION OF CO

Abstract

ABSTRACT Silver-cobalt and silver-manganese composite oxides were prepared by co-precipitation method at different metal/metal oxide molar ratio and by different rates of preparation. The catalysts were characterised by X-Ray diffraction, BET and TGA. The CO oxidation studies were carried out in a micro reactor and reaction was formed under dry and wet atmospheres for a binary CO + air and CO + CO 2   H 2 O + air gas mixtures. 1:1 Ag/Co prepared by the slow precipitation and 1:1 Ag/Mn prepared by the opposite slow precipitation gave the best performance for the dry conditions. Activity of these catalysts significantly decreased when the water vapor and CO 2 was added to the feed. Silver-cobalt composite oxide catalyst shows a higher performance than the silver-manganese composite oxide catalyst for the wet atmospheres.   Keywords: CO oxidation, catalyst, co-precipitation, low-temperature