The mechanism of the reaction of nitrogen oxide with ammonia over Cr 2O 3Al 2O 3 and Cr 2O 3 catalysts : I. Characterization of the catalysts

Abstract

Catalytic activities of various Cr 2O 3Al 2O 3 catalysts for the reaction of nitrogen oxide (NO) with ammonia (NH 3) were determined. The activity, when plotted against Cr contents, showed two maxima, at 9.3% Cr and 100% Cr, respectively. X-Ray examination showed that γ-phase and α-phase solid solution occurred at low and high Cr contents, respectively. The BET area, reducibility and the amount of irreversibly adsorbed NO also showed their maxima at 9.3% Cr. Such properties explain, at least partially, the activity pattern in the low Crcontent region.