NO presence effects on the reduction of N2O by CO over Al–Pd–Co oxide catalyst

Nitrous oxide (N2O) is known as one of the greenhouse gases of which the emission levels are to be controlled and also an ozone-depleting material in the stratosphere. For more than a last couple of decades, various catalysts have been investigated for the reduction of N2O emission. However, most of those catalysts require reaction temperatures as high as 450 °C even with the use of effective reducing agents. Furthermore, NO, which is usually present with N2O, significantly interferes with the removal efficiency of N2O. Al–Pd–Co oxide catalyst which is a type of mixed metal oxides (MMO) has shown 100% conversion of N2O at temperatures as low as 200 °C using CO. This paper examines the effect of NO on the reduction of N2O with CO over Al–Pd–Co oxide catalyst. The experiments were carried out in the temperature range of 100–500 °C with space velocity of 10,000–50,000 h−1. Though the efficiency of N2O reduction is decreased significantly when NO is present, the efficiency increases when sufficient CO is supplied. In this study, the reduction mechanisms of N2O and NO by CO have been confirmed, and it was shown that MMO catalyst can simultaneously remove N2O and NO using CO with high efficiency.