Reducing N2O Formation over CO‐SCR Systems with CuCe Mixed Metal Oxides

In the CO‐SCR reaction, reducing by‐product N2O formation helps to convert more NO into clean N2, which has a great significance to environmental governance. In this study, the CuCe mixed metal oxides with different molar ratios of Cu to Ce were prepared, characterized and evaluated to study the effect on the products of NO reduction by CO. The experimental results showed that the CuCe‐1 : 3 catalyst showed superior NO conversion with over 90 % N2 selectivity in the operating temperature window, and there were no amounts of N2O by‐product at 50–200 °C. The higher oxygen vacancy concentration and appearance of (NO)2 dimer inhibited N2O formation at low temperature. Finally, the reaction paths for the CuCe catalysts generating different products (N2, N2O) were proposed in the CO‐SCR reaction based on in‐situ DRIFTS results. CO‐SCR Systems: In this study, different ratios of CuCe catalysts were prepared to reduce the by‐product N2O during the CO‐SCR reaction. The CuCe‐1 : 3 catalyst not only exhibited excellent catalytic performance, but also produced no by‐product N2O. The CuCe‐1 : 3 catalyst only generated N2 at low temperature due to its high oxygen vacancy concentration and the presence of (NO)2 dimer. The formation mechanisms of N2 and N2O products are proposed based on in‐situ DRIFTS results.