Effects of MoO3 and CeO2 doping on the decomposition and reactivity of NH4HSO4 on V2O5/TiO2 catalysts

The deposition of NH 4 HSO 4 on catalysts is one of the key issues for selective catalytic reduction of NO x . In this study, NH 4 HSO 4 was preloaded on catalysts, and the effects of MoO 3 and CeO 2 doping on the decomposition and reactivity of NH 4 HSO 4 on V 2 O 5 /TiO 2 catalysts are studied. The results show that the introduction of MoO 3 and CeO 2 significantly promoted NO x conversion on the V 2 O 5 /TiO 2 catalysts. Doping with MoO 3 could effectively enhance the S and H 2 O resistance of the catalysts. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicate that it is the strong chemical interactions between NH 4 HSO 4 and the catalysts that are adverse to the decomposition of NH 4 HSO 4 . However, doping with MoO 3 apparently inhibits these interactions, which significantly decrease the decomposition temperature of NH 4 HSO 4 . In situ FTIR experiments show that the NH 4 + in preloaded NH 4 HSO 4 could react with gaseous NO on catalysts, and doping with MoO 3 could facilitate the reaction rate.