Catalytic properties of activated carbons oxidized, treated with N-compounds, and promoted with copper were studied in selective catalytic reduction NOX by ammonia (NH3-SCR). The modification of the catalysts consisted of a series of steps (pre-oxidation of activated carbon, impregnation with urea, impregnation with copper). The physicochemical properties of the obtained samples were determined using X-ray diffraction, FT-IR spectroscopy, and low-temperature N2 sorption. The modification with copper improved the catalytic activity and stability of the catalysts. All the functionalized carbon doped with copper reached more than 90% of NO conversion and CO2 did not exceed 240 ppm at 220 ◦C. The sample doped with 5 wt.% Cu had the maximum NO conversion of 98% at 300 ◦C. The maximum N2O concentration detected for the same sample was only 55 ppm, which confirmed its selectivity.
Eutectic copper oxides (Cu2O) crystallize during the copper solidification process in the ETP grade copper which leads to high oxygen concentrations in interdendritic spaces. It has been experimentally found that they can be regular or elongated, and their size reaches several micrometres. During the multi-cage hot rolling process, homogenization of the oxide distribution in the entire volume of the wire rod occurs. This process is carried out in the soft copper matrix. Throughout the drawing process the fragmentation of oxides transpires along with changes in the shape from angular to more oval in a degree depending on the size of the deformation (wire diameter). Microcracks, fissures and local stress fields in the reinforced copper matrix arise around the oxide particles. The article presents the results of research on the evolution of copper oxides in ingots, wire rods and wires. The results of investigations of the wires properties and the limitations of the drawing process, especially of microwires, are presented.