Design of Bifunctional Cu-SSZ-13@Mn2Cu1Al1Ox Core–Shell Catalyst with Superior Activity for the Simultaneous Removal of VOCs and NOx

Synchronous control of volatile organic compounds (VOCs) and nitrogen oxides (NO_x) is of great importance for ozone and PM_2.5 pollution control. Balancing VOC oxidation and the NH₃-SCR reaction is the key to achieving the simultaneous removal of these two pollutants. In this work, a vertically oriented Mn₂Cu₁Al₁O_x nanosheet is grown in situ on the surface of Cu-SSZ-13 to synthesize a core-shell bifunctional catalyst (Cu-SSZ-13@Mn₂Cu₁Al₁O_x) with multiple active sites. The optimized Cu-SSZ-13@Mn₂Cu₁Al₁O_x catalyst delivered excellent performance for the simultaneous removal of VOCs and NO_x with both 100% conversion at 300 °C in the presence of 5% water vapor. Physicochemical characterization and density functional theory (DFT) calculations revealed that Cu-SSZ-13@Mn₂Cu₁Al₁O_x possesses more surface acidity and oxygen vacancies. The charge transfer between the core and shell is the intrinsic reason for the improved activity for both VOC and NO_x removal. The molecular orbital theory is used to explain the different adsorption energies due to the different bonding modes between the core-shell and mixed individual catalysts. This work provides a novel strategy for designing efficient catalysts for the simultaneous removal of VOCs and NO_x or other multiple pollutants.