Abstract
The replacement of noble metal-based catalytic systems with oxide catalysts based on transition metals of variable valency for the oxidation of carbon monoxide, the reduction of catalyst production costs, and simultaneously the reduction of energy costs for carrying out the reaction is a pressing issue. In this work, binary copper ferrites and ternary copper-manganese-iron oxide systems were synthesized for low- temperature carbon monoxide oxidation using the sol-gel method with self-combustion, as well as using microwave technology. The samples were characterized using X-ray diffraction technique, infrared spectroscopy, and thermogravimetric differential thermal analysis methods, their specific surface area was measured by the BET method, and microphotographs were taken using a scanning electron microscope. The adsorption of carbon monoxide on catalysts has also been studied. It has been found that the resulting binary and ternary copper-containing oxide systems are multiphase systems containing ferrites, manganites, and oxides of copper, manganese and iron. The resulting catalysts are active in the low-temperature carbon monoxide oxidation in the temperature range of 145-180ºC. In the systems, an enhancing effect of the influence of its components – oxide and spinel (ferrite) phases – on the catalytic activity is observed. Due to thermal desorption data, for the studied catalysts on which the oxidation of carbon monoxide occurs at sufficiently low temperatures, carbon monoxide adsorption is observed approximately in the same range. The appearance of various structural defects during short-term combustion of the gel without additional heat treatment, which can be considered as catalytically active centers, on the one hand, and the presence of oxide and spinel phases in the catalyst composition, which exhibit a mutually reinforcing effect, on the other hand, are the advantages of this synthesis method active catalysts for low temperature oxidation of carbon monoxide to carbon dioxide.