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

Abstract

The synergetic catalytic removal of nitrogen oxides (NOx) 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 NOx 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 NOx 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.