Catalytic oxidation and capture of elemental mercury from simulated flue gas using Mn-doped titanium dioxide

• Published in: The Korean journal of chemical engineering Vol. 33; no. 6; pp. 1823 - 1830
• Main Authors: Zhi, Jingtao, Yu, Xianqun, Bao, Jingjing, Jiang, Xiaoxiang, Yang, Hongmin
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2016; 한국화학공학회
• Subjects: Biotechnology; Catalysis; Chemistry; Chemistry and Materials Science; Environmental Engineering; Industrial Chemistry/Chemical Engineering; Materials Science; 화학공학; Catalytic Oxidation; Removal; Elemental Mercury; Mn-doped Titanium Dioxide
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-016-0026-5

Titanium dioxide (TiO 2 ) and Mn-doped TiO 2 (Mn( x )-TiO 2 ) were synthesized in a sol-gel method and characterized by BET surface area analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Gasphase elemental mercury (Hg 0 ) oxidation and capture by the Mn-doped TiO 2 catalyst was studied in the simulated flue gas in a fixed-bed reactor. The investigation of the influence of Mn loading, flue gas components (SO 2 , NO, O 2 , and H 2 O) showed that the Hg 0 capture capability of Mn( x )-TiO 2 was much higher than that of pure TiO 2 . The addition of Mn inhibits the grain growth of TiO 2 and improves the porous structure parameters of Mn( x )-TiO 2 . Excellent Hg 0 oxidation performance was observed with the catalyst with 10% of Mn loading ratio and 97% of Hg 0 oxidation was achieved under the test condition (120 °C, N 2 /6%O 2 ). The presence of O 2 and NO had positive effect on the Hg 0 removal efficiency, while mercury capture capacity was reduced in the presence of SO 2 and H 2 O. XPS spectra results reveal that the mercury is mainly present in its oxidized form (HgO) in the spent catalyst and Mn 4+ doped on the surface of TiO 2 is partially converted into Mn 3+ which indicates Mn and the lattice oxygen are involved in Hg 0 oxidation reactions.