Synergistic catalytic removal of NO_x and chlorinated aromatics via atomically dispersed asymmetric Mn-O-Ce sites on montmorillonite

The synergistic catalytic removal of nitrogen oxides (NO_x) and chlorinated volatile organic compounds (CVOC) is in significant demand from both ecological and economic perspectives. Breaking the trade-off between synergistic catalytic activity and selectivity is a big challenge. In this study, we developed a catalyst named MnCeO_x/MMT-Ti, which features an atomically dispersed MnCeO_x supported on montmorillonite. It exhibited superior performance from 260 to 330 °C, achieving over 80 % conversion of NO_x and chlorobenzene (CB), as well as over 80 % selectivity for N₂ and CO₂. Atomically dispersed asymmetric Mn-O-Ce sites were constructed and evidenced. The isolated asymmetric Mn-O-Ce sites in MnCeO_x/MMT-Ti stimulated exceptional O₂ adsorption and activation, facilitating CB oxidation through a variant Mars-van Krevelen mechanism while improving the N₂ selectivity of NO_x reduction. In addition, the abundant Brønsted acid sites from montmorillonite ensured the Cl-resistance and high stability of the catalyst. This study presents a novel approach for the synergistic removal of NO_x and VOCs via tailoring atomically dispersed active sites of synergistic catalysts composed of complex oxides.