Simultaneous removal of NO_x and VOCs by Si doping CeO₂ based catalysts: An acidity and redox properties balance strategy

The synergetic catalytic removal of nitrogen oxides (NO_x) and volatile organic compounds (VOCs) exhibits huge potentials in reducing cost with high efficiency in the field of environmental catalysis, the key point is to adjust the balance of acidity and oxidizability over one catalyst. Herein, we develop a modifited CeO₂-based catalyst by doping Si to balance acidity and redox properties. Consequently, the mosted optimizted Si-doped CeO₂ catalyst showed superior synergistic removal of NO_x and toluene compared to pure CeO₂. It was demonstrated that Si-doped CeO₂ improved markedly the number of acidic sites, increased the Ce³⁺ concentration, and adjusted the adsorption interaction between catalyst and NH₃/toluene. These led to a wider temperature window of 300–375 °C for the simultaneous removal of NO_x and toluene. It is believed that this work provides a simple strategy to balance acidity and redox properties and offers novel insights for multi-pollutant removal catalyst design.