Systematic effects of Fe doping on the activity of V2O5/TiO2-carbon nanotube catalyst for NH3-SCR of NOx

Abstract

The present investigation concentrates on the reduction of NOx emissions, the indirect greenhouse gases, which generate ozone by reacting with the atmosphere. A series of composite catalytic support (TiO2-CNTs) with a constant TiO2-CNT ratio prepared by precipitation method was utilized to synthesize Fe-modified V2O5/TiO2-CNT catalyst for selective catalytic reduction (SCR) of NOx with ammonia (NH3). The structural and surface characteristics of the prepared catalyst were investigated by using Brunauer–Emmett–Teller surface area measurement, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, and temperature-programmed desorption (TPD) techniques. In terms of catalytic activity, VFe3TiC10 catalyst showed better SCR performance having a NOx conversion efficiency of 95% and 98% at 250 °C and 300 °C, respectively. The improved performance could be attributed to high surface chemisorbed oxygen on the surface of the catalyst by the added Fe species which promotes the SCR activity. The catalytic activity results depicted that the addition of CNTs to TiO2 support enhanced the SCR activity of the catalyst at low reaction temperatures and it also provides better resistance to SO2. In addition, the effects of Fe modification on the NH3 removal efficiency of the catalyst were also investigated.