GASEOUS ELEMENTAL MERCURY CAPTURE BY NOVEL COPPER-DOPED (Fe2.2Mn0.8)1−δO4 ADSORBENTS

Abstract

A series of (Fe[Formula: see text]Mn[Formula: see text]Cu[Formula: see text]O4 ([Formula: see text], 0.2, 0.5, and 0.8) was synthesized for elemental mercury capture. The as-synthesized adsorbents were characterized by Brunauer–Emmett–Teller (BET), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that (Fe[Formula: see text]Mn[Formula: see text]Cu[Formula: see text]O4 catalyst adsorbent exhibits the best elemental mercury capture capacity with the increase in mercury removal efficiency by 20% as compared to the (Fe[Formula: see text]Mn[Formula: see text]O4 adsorbent. The XPS results indicate Cu dopant can provide the lattice oxygen on the adsorbent surface due to the transformation from Cu[Formula: see text] cations to Cu[Formula: see text] cations, which increases the active sites for elemental mercury adsorption. The Mn[Formula: see text] cations on the adsorbent surface may oxidize the adsorbed mercury to mercury oxidization. Meanwhile, the Mn[Formula: see text] cations formed are also oxidized to the Mn[Formula: see text] cations by the gaseous oxygen phase in the reactor gas. However, the large Cu content may block the collision between Mn[Formula: see text] cations and adsorbed mercury, and thus decrease the oxidization capability of adsorbent surface for mercury. Therefore, the Cu dopant with the suitable content may be a potential modified method for the adsorbent to further increase the elemental mercury capture.