Fe/Beta@meso-CeO₂ core–shell catalyst with abundant mesopores was designed and controllablly constructed by a template-assisted self-assembly method. This catalyst was fabricated by small-grain Beta molecular sieve supporting FeO_x nanoparticles as the core and thin meso-CeO₂ film (~ 2 nm) as the shell, and it exhibits remarkable resistance to potassium poisoning and superior SO₂ tolerance for selective catalytic reduction (SCR) of NO_x with NH₃. Meso-CeO₂ shells play a key role in influencing the acidity and redox properties of catalyst. It can not only serve as an effective protective “layer” to prevent K from exchanging the isolated iron ions to form oligonuclear Fe_xO_y clusters, but also increase chemisorbed oxygen species and promote the formation of active NO₂ and cis-N₂O₂⁻ species. Moreover, meso-CeO₂ thin film can suppress the generation of sulfate species blocking the active sites over Fe/Beta@meso-CeO₂ catalyst. Furthermore, the kinetics result further reveals that the coating of meso-CeO₂ shell doesn’t change E_a for the SCR reaction, and the decreased kinetic rate for K-poisoning catalyst is caused by the decreased number of active sites for the reaction. Therefore, the present study provides a new path for synthesis and application of core–shell structural catalysts.

利用模板辅助自组装方法设计并控制了Fe / Beta @ meso-CeO ₂核壳催化剂的中孔含量。该催化剂是由以FeO _x纳米粒子为核，以中观CeO ₂薄膜（〜2 nm）为壳的小颗粒Beta分子筛制成的，具有出色的抗钾中毒能力和对选择性催化的优异SO ₂耐受性。用NH ₃还原NO _x（SCR）。介孔铈₂壳在影响催化剂的酸度和氧化还原特性方面起着关键作用。它不仅可以作为有效的保护性的“层”，以防止从ķ交换的分离的铁离子形成的Fe oligonuclear _X ø _ý簇，而且还增加化学吸附氧物种和促进的活性的形成NO ₂和CIS -N ₂ ö ₂ ^-种。此外，内消旋CeO ₂薄膜可以抑制硫酸盐物种的生成，从而阻止Fe / Beta @ meso-CeO ₂催化剂上的活性位。此外，动力学结果进一步表明，介孔CeO ₂壳的涂层不会改变ESCR反应的_α为_α，而K中毒催化剂的动力学速率降低是由于该反应的活性位点数量减少。因此，本研究为核-壳结构催化剂的合成和应用提供了一条新途径。