Effect of Copper Precursors on Catalytic Performance Over CuO–CeO 2 Toward NH 3 ‐SCR Reaction
Jiarui Li, Zhongxian Song, Xuejun Zhang, Yanhui Yang, Xi Chen, Zhenzhen Huang, Wei Liu, Huixin YuABSTRACT
The NH 3 ‐SCR performance of CuO‐CeO 2 catalysts is highly sensitive to the selection of copper precursors, yet the structure‐activity relationship under the influence of phosphorus‐containing precursors has not been systematically elucidated to date. Herein, CuCe(P) was first prepared via coprecipitation using copper phosphate precursor and systematically compared with CuCe(N) and CuCe(S) from conventional copper nitrate and sulfate, respectively. The results showed that the CuCe(P) catalyst reached a NO x conversion rate of 89.5% at 300°C with an N 2 selectivity of 95% at 350°C–450°C. The introduction of PO 4 3− enhanced interactions between CuO x and CeO 2 support, promoting oxygen vacancy formation, increasing surface acidity, and reactive oxygen species concentration. Lewis acid sites were the primary species on the surface of the CuCe(P) catalyst. NH 3 was mainly adsorbed onto these acid sites and participated in the reaction process. The catalyst operated via both the Eley‐Rideal mechanism and the Langmuir‐Hinshelwood mechanism in parallel. Furthermore, excessive nitrate species formation was effectively suppressed by phosphate modification, which reduced the occupation of active sites. This study provides scientific guidance for the rational design of phosphorus‐modified Cu‐Ce based SCR catalysts and an effective approach to address the key challenge of balancing activity and selectivity in medium‐to‐high‐temperature SCR catalysis.