Promotional effect of phosphorus modification on improving the Na resistance of V2O5-MoO3/TiO2 catalyst for selective catalytic reduction of NOx by NH3

Abstract Improving the resistance to alkali metals poisoning of commercial V2O5-TiO2 based catalyst could significantly enhance its service life. In this work, a simple method of incorporating P species was developed to enhance the resistance to Na species of commercial V2O5-MoO3/TiO2 (V-Mo/Ti) catalyst. XRD and N2-adsorption results proposed that P adding have no obvious influence on the structure of V-Mo/Ti. However, the results referred from the H2-TPR, XPS, NH3-TPD and NH3-DRIFTS suggested that Na species preferentially reacted with P species than V2O5 species, which preserved most of redox sites (V = O structure) and acid sites (V−OH structure) on V-Mo-P/Ti catalyst. Thus, V-Mo-P-Na/Ti presented a much higher NH3-SCR activity than V-Mo-Na/Ti. Finally, possible promotional mechanism of P modification on improving Na resistance of V-Mo/Ti catalyst was proposed. We expect this work could contributed to the studies on preparing high effective NH3-SCR catalysts.