Ce–Ti catalysts modified with copper and vanadium to effectively remove slip NH3 and NOx from coal-fired plants

Abstract

In this work, V/Ce–Ti catalysts were modified with different kinds of transition metals (Cu, Fe, Co, Mn) by sol–gel and impregnation methods. The NH3 oxidation performance of them was tested to select the most active catalyst in NH3-selective catalytic oxidation (NH3–SCO). The effect of NO, SO2 and H2O was also investigated. The experimental results indicate that 1% Cu–V/Ce–Ti catalyst exhibits the most significant ability to remove slip ammonia discharged from coal-fired plants and its NH3 conversion efficiency reaches 90% at 300 °C. In addition, 97% NOx can be removed when NO is introduced in the gas. Cu–V/Ce–Ti catalyst also obtains good resistance to H2O and SO2. Based on the characterization experiment, the introduced Cu and V are highly dispersed on Ce–Ti catalyst and they can increase the redox properties and the number of acidic sites. Besides, the redox cycles among Cu, V and Ce species on Cu–V/Ce–Ti catalyst surface are conducive to generating more active oxygen and promoting the oxidation capacity of the catalyst.