Atomic‐Level Design of Acid–Base Pairs in Oxides for Selective Catalytic Reduction of Nitrogen Oxides with Ammonia
Guoquan Liu, He Zhang, Pengfei Wang, Chao Gao, Zechao Zhuang, Dingsheng Wang, Sihui Zhan
Abstract
Abstract Selective catalytic reduction of nitrogen oxides (NO x ) with NH 3 (NH 3 ‐SCR) poses considerable potential in the abatement of NO x emissions. However, the efficient adsorption and speedy reaction of reactants following the specific mechanism in a favorable way is still a challenge for enhancing catalysis. Herein, we propose the strategy aimed at adjusting electronic properties of Ce‐O v ‐W acid–base pairs through constructing oxygen vacancies on Ce/WO x , thereby fostering SCR activity. Experimental and theoretical results reveal that Ce‐O v ‐W acid–base pairs not only provide more Ce 3+ sites for promoting the reactivity of adsorbed NO, but also accelerate the reaction between NH 3 and gaseous NO owing to the generation of W 5+ species with superior surface acidity, which enhance Langmuir–Hinshelwood and Eley–Rideal mechanisms, respectively. Consequently, the designed catalysts achieve over 90% NO x conversion above 250 °C and exhibit higher activity than normal Ce/WO 3 and V/W‐TiO 2 commercial catalysts, with anti‐poisoning of SO 2 and H 2 O under harsh working conditions, expecting to provide the guidance for promoting de‐NO x industrial application.