Investigation of NO desorption from the surface of CuO/γ-Al2O3 catalysts, particularly in the presence of a reductant

Abstract

The process of NO desorption from the surface of supported copper-containing catalysts CuO/ γ -Al 2 O 3 was studied in dependence on temperature. Therewith, the preliminary adsorption of NO was carried out both in an inert argon medium and in the presence of oxygen. It was shown that the presence of oxygen considerably increased the capacity of samples with respect to NO owing to the additional redox mechanism. Besides, the desorption temperature maximum shifted toward higher temperatures. For the sample with the highest capacity to NO, the desorption was performed in the presence of hydrogen or propane as a reductant. Desorption in the presence of hydrogen led to the reduction of adsorbed species at a temperature of 160–190 °C. In the presence of propane, NO x was desorbed mostly due to thermal destruction of adsorbed nitrogen species to NO in the temperature range of 180–250 °C, similar to the case of inert atmosphere. The contribution of reduction due to the presence of propane showed up at a temperature of 260–300 °C.