LaFeO₃ perovskite nanoparticles for efficient capture of elemental mercury from coal-fired flue gas

LaFeO3 perovskite was synthesized by sol-gel method and calcination method and used to remove mercury in flue gas. Three kinds of metal oxides La2O3, Fe2O3, and LaFeO3 were evaluated. The results indicated that the performances for Hg-0 removal decreased in the order of LaFeO3 > Fe2O3 > La2O3. LaFeO3 has similar to 94% removal efficiency at 120 celcius. To explore the temperature response range and the influence of simulated flue gas, the performance of LaFeO3 to remove Hg-0 under O-2, NO, SO2, and different temperature conditions was further examined. Furthermore, LaFeO3 is repeat-ability. The characterization results showed that the Hg-0 transition to HgO is due to the valence change of iron and the release of lattice oxygen. In addition, density functional theory (DFT) was conducted to calculate the density of states to verify the performance of the sample. This work shows that LaFeO3 is a promising adsorbent for mercury removal from flue gas in coal-fired power plants.