Enhancement of Ce1−xSnxO2 support in LaMnO3 for the catalytic oxidation and adsorption of elemental mercury†
Abstract
Mn-based perovskite oxide was used as the active site for elemental mercury (Hg0) removal from coal-fired flue gas. Ce1−xSnxO2 binary oxides were selected as the catalyst supports for LaMnO3 to enhance the catalytic oxidation and adsorption performance. Ce0.7Sn0.3O2 had the best Hg0 removal performance among the as-prepared Ce1−xSnxO2 binary oxides; the Hg0 removal efficiency was 95.2% at 350 °C. LaMnO3 had better performance at low temperatures (<200 °C). LaMnO3/Ce0.7Sn0.3O2 enlarged the reaction temperature window and enhanced the Hg0 removal efficiencies. The correlation between the physicochemical properties and the catalytic removal performance was investigated by XRD, BET surface area measurements, Raman spectroscopy, H2-TPR and XPS analysis. With the addition of Ce–Sn binary oxides as catalyst support, the surface areas of LaMnO3 was enlarged, the reducibility was enhanced and the oxygen mobility was improved. In addition, the Hg0 removal mechanism was illustrated on the basis of the experimental results. The roles of Ce, Sn and LaMnO3 were also discussed in this study.