Fe–Ce Mixed Oxides Supported on Carbon Nanotubes for Simultaneous Removal of NO and Hg0 in Flue Gas

Abstract

Developing simultaneous removal technology of NOx and Hg0 in flue gas is highly desirable but remains challenging. Multiwalled carbon nanotube supported Fe–Ce mixed oxide nanoparticles (Fe(2)Ce(0.5)Ox/MWCNTs) were prepared using the ethanol impregnation method for DeNOx and Hg0 removal. The NO and Hg0 removal efficiencies over catalyst reached to 99.1% and 88.9% at 240 °C and a space velocity of 30 000 h–1. The Fe–Ce mixed oxides supported both inside and outside of MWCNTs in highly dispersed form with particle size of 3–5 nm. The Ce4+ existed on MWCNTs in two forms, some of which are the fluorite-like crystal CeO2; the other portion of Ce4+ entered the spinel structure of γ-Fe2O3 and led to the distortion of the γ-Fe2O3 lattice. Furthermore, it is evident that the chemisorbed oxygen content and oxidation activity of catalysts increased dramatically after Ce doping, which could be attributed to the excellent NH3-SCR and Hg0 removal performance.