Simultaneous removal of elemental mercury and NO from flue gas by V2O5-CeO2/TiO2 catalysts

A series of Ce-doped V2O5/TiO2 catalysts synthesized by an ultrasound assisted impregnation method were employed to investigate simultaneous removal of elemental mercury (Hg) and NO in lab-scale experiments. Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), X-ray diffractogram (XRD), and X-ray photoelectron spectroscopy (XPS) analyses were used to characterize the samples. Compared to TiO2 support, the catalytic performance of CeO2 doped on both TiO2 and V2O5/TiO2 catalysts have been improved. Remarkably, 1%V2O5-10% CeO2/TiO2 (V1Ce10Ti) exhibited the highest Hg oxidation efficiency of 81.55% at 250 degrees C with a desired NO removal efficiency under the same condition. Both the NO conversion and Hg oxidation efficiency were enhanced in the presence of O-2. The activity was inhibited by the injection of NH3 with the increase of NH3/NO. When in the presence of 400 ppm SO2, Hg oxidation was slightly affected. Furthermore, Hg removal behavior under both oxidation and selective catalytic reduction (SCR) condition over V1Ce10Ti were well investigated to further probe into the feasibility of one single unit for multi-pollutants control in industry application. The existence of the redox cycle of V4+ + Ce4+ <-> V5+ + Ce3+ in V2O5 CeO2/TiO2 catalyst could not only greatly improve the NO conversion, but also promote the oxidation of Hg. (C) 2015 Elsevier B.V. All rights reserved.