Insights into the Ce-doping CuCoAlO with superior resistance to alkali metal poisons for CO-SCR removal of NOx

It is undeniable that catalyst poisoning and deactivation ascribed to alkali metals in exhaust gas is still a thorny matter in selective catalytic reduction of NOx. Herein, under the premise of maintaining the excellent activity of CuCoAlO, Ce doping validly boosts the 3 wt% K resistance of the catalyst, the NOx conversion rate reaches 91% at 250 °C, which is 60% higher than the unmodified K poisoning catalyst. By tracking the evolution of reaction intermediates and combining the theoretical calculation, it was found that the reduced cumulative coverage of stable nitrate species is the main reason for the enhanced alkali resistance. Notably, the introduction of Ce efficiently preserves the reducibility and provides a considerable amount of surface adsorbed oxygen, which accelerates the activation of CO and NO and further benefits the CO-SCR. Hoping this work will provide an inspiration for the design of SCR catalysts with more reliable and distinguished alkaline resistance.