SO2 promotion in NH3-SCR reaction over V2O5/SiC catalyst at low temperature

- Silicon carbide supported vanadium catalysts were prepared by pore volume impregnation method.
- SO2 show a promotion effect on the carbon-based catalyst at low temperature.
- Carbon play an important role on SO2 promotion effect.

Silicon carbide (SiC) supported vanadium catalysts were obtained using the wet chemical impregnation method, and their removal of NOx with the presence of SO2 at low temperature was evaluated. The effect of carbon was observed by comparing different carbon-based catalysts. V2O5/SiC (1 wt.%) catalyst had a NOx removal efficiency of 86% in the presence of SO2 at 250 °C with a GHSV of 180,000 h−1. In this study, the temperature-programmed desorption of NH3 (NH3-TPD) and temperature-programmed decomposition (TPDC) of NH4HSO4 deposited on the catalysts and reaction were performed to determine the influence of carbon on the performance of a carbon-based catalyst in the presence of SO2. The NO on the carbon support can effectively react with the NH4HSO4 formed on the catalyst surface at low temperatures. Additionally, the adsorption of NH3 was higher on carbon-based catalysts that were pre-adsorbed with SO2 + O2. Thus, SO2 promotes the activity of a carbon-based catalyst at low temperatures, and carbon has very important effect on the promotion of that activity.