Low temperature selective catalytic reduction of NO and NO 2 with NH 3 over activated carbon-supported vanadium oxide catalyst

Abstract

Selective catalytic reduction (SCR) of NO and NO 2 with ammonia was investigated over activated carbon-supported vanadium oxide (V 2O 5/AC) catalyst. The results show that high activity and selectivity could be achieved in wide range of temperatures and space velocities. NO x conversion to N 2 increases with increasing NO 2/NO x ratio, and the increase vanishes gradually with increasing temperature. An increase of NO x conversion to N 2 from 26% to 94% can be achieved at a temperature as low as 150 °C without the formation of NH 4NO 3. The results of temperature programmed desorption (TPD) and infrared (IR) spectrometry experiments show that NH 4NO 3 could be deposited on the catalyst at 100 °C and decomposed to NH 3, N 2O, and NO around 130 °C. To explain the observed behaviors, AC involved NO 2-SCR process was proposed, in which NH 4NO 3 is reduced to N 2 by AC instead of NO. This process shows better reactivity at lower temperatures.