Mercury capture by manganese modified copper oxide

Abstract

Abstract To increase elemental mercury removal efficiency of CuO without HCl gas, the Mn-modified CuO samples were proposed. In this work, four doping ratios of Mn to CuO were fabricated by a hydrothermal synthesis method. The surface morphologies, crystalline structures and chemical states of as-prepared sorbents were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The results showed that all the Mn-modified samples contained the CuMnO2 phase with different contents. The Hg0 removal experimental results indicated that the Mn-modified CuO sorbents had the higher elemental mercury removal efficiency than pure CuO. The pseudo-first-order kinetic model fitted well to the adsorption experimental data. The CuMnO2 content in sorbents had a positive effect on mercury capture. We speculated that CuMnO2 acted as a dominant factor for the mercury removal capacity of Mn-modified CuO sorbents. The high valance Mn oxidized the elemental mercury to oxidized mercury. Moreover, CuO can re-oxidize the low valance Mn to the high valance, resulting in the further increase in Hg0 removal efficiency.