Enhancing effect of lanthanum doping on anti-thermal aging performance for Cu/CeZrO2 three-way catalyst

Abstract

Copper-based catalysts exhibit excellent three-way catalytic activity but tend to undergo agglomeration at high temperatures, resulting in inadequate thermal stability. This study focuses on construction of strong metal-support interactions through La doping to improve the thermal stability and resistance to thermal aging of the catalysts. Cu/CeZrLaO2 demonstrates superior thermal aging resistance even after thermal aged at 1000 °C for 3 h, which still maintains 88% and 100% for CO and HC conversion, and more than 65% NO conversion at the simulated vehicle exhaust atmosphere. The introduction of La into the CeZrO2 support forms Ce-Zr-La-O ternary solid solution, enhancing the structural stability and suppressing grain growth at elevated temperatures. Meanwhile, the doping of this trivalent generates a large number of oxygen vacancies in the catalyst, which improves the dispersion of copper through the anchoring effect. Crucially, La substantially strengthens the metal-support interaction, preventing sintering and agglomeration of copper under harsh conditions, ultimately maintaining the dispersion of copper on the catalyst surface. The present work effectively improves the thermal stability of the Cu/CeZrO2 catalyst, establishing a foundation for the further industrial application of the copper-based three-way catalyst.