Different crystal-forms of one-dimensional MnO2 nanomaterials for the catalytic oxidation and adsorption of elemental mercury

摘要: MnO2 has been found to be a promising material capture elemental mercury (Hg(0)) from waste gases. To investigate the structure effect on Hg(0) uptake, three types of one-dimensional (1D) nano-particles, α-, β- and γ-MnO2, were successfully prepared tested. The structures γ-MnO2 characterized by XRD, BET, TEM SEM. results indicate that present in morphologies belt-, rod- spindle-like 1D materials, respectively. These findings demonstrated noticeably different activities capturing Hg(0), depending surface area crystalline structure. performance enhancement is order of: β-MnO2<γ-MnO2<α-MnO2 at 150°C. mechanism for removal using was discussed with help H2-TPR, XPS experiments absence O2. It determined oxidizability forms increased as follows: β-MnO2<γ-MnO2<α-MnO2. ascribed catalytic oxidation reduction Mn(4+)→Mn(3+)→Mn(2+). Furthermore, interaction forces between manganese oxide sites are increase following order: based desorption tests.