Abstract
Hydrotalcitelike Co-Al and Ni-Al catalysts of different compositions (with the atomic ratio M2+/Al3+ = 0.5-3.0) were studied in the reaction of selective reduction of NO by propane, propylene, and n-decane in the presence of O-2. The higher activity of the catalysts with M2+/Al3+ = 0.5 is connected with high dispersity of Ni or Co cations stabilized by a significant amount of Al3+ ions. Propylene was shown to be the most efficient reducing agent for nitrogen oxide. The highest degree of conversion to the extent of 90-99% was attained at 400 and 420-440 degrees C for Ni-Al and Co-Al samples, respectively. When propane and decane were used as reducing agents, the conversion of both catalysts was characterized by the volcano-shaped dependence on temperature due to the fact that the catalyst took part in the concurrent reaction of hydrocarbon (reducing agent) oxidation. Hydrotalcitelike materials are promising representatives of inexpensive bi- and multicomponent systems. The design strategy for new active catalysts for processes of purification of gas exhausts from NOx, that are stable in the presence of water and sulfur oxides, may be based on usage of hydrotalcites with modified ions introduced into them.