Elemental mercury removal by CeO2/TiO2-PILCs under simulated coal-fired flue gas

Abstract CeO 2 /TiO 2 -PILCs with different Ce loading were synthesized by an impregnation method for Hg 0 removal in flue gas considering the effect of various flue gas compositions. Nitrogen adsorption–desorption, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectrometer were employed for material characterization. The mechanisms of the effect of gas compositions on Hg 0 oxidation were discovered in detail in this paper. The results demonstrated that 15% Ce/Ti-PILC has the best Hg 0 oxidation efficiency at 300 °C under N 2  + O 2 due to the redox switch of Ce 4+ /Ce 3+ . The presence of SO 2 in flue gas could restrain the oxidation activity by generating SO 4 2− on 15% Ce/Ti-PILC surface. Hg 0 oxidation was enhanced by HCl in flue gas because of the Deacon mechanism. NO 2 was detected on the catalyst surface when NO was introduced into the in flue gas, which was responsible for the promotional effect of NO on Hg 0 oxidation. The prohibitive influence of NH 3 and H 2 O on Hg 0 oxidation was obvious, which was due to the competitive adsorption. CeO 2 /TiO 2 -PILCs was demonstrated to be a potential catalysts for Hg 0 oxidation in flue gas.