In Situ Decoration of Selenide on Copper Foam for the Efficient Immobilization of Gaseous Elemental Mercury.

Mercury emission from industrial activities is a great threat to public health and ecosystems. Developing new strategies and materials to remove mercury still remains a serious task. Herein, selenide-decorated copper foam prepared by a heating-stirring method (Cu-hs) was used as a monolithic mercury adsorption material. The Cu-hs exhibited much better adsorption of elemental mercury (Hg0) compared with the selenide-decorated cordierite honeycomb prepared by the same method (Cordierite-hs). Nearly 100% Hg0 adsorption efficiency was obtained under a high gaseous hourly space velocity of 6.0 × 104. Excellent Hg0 adsorption capacity was obtained in a wide range of reaction temperatures from 40 to 120 °C, suggesting the good adaptability of Cu-hs in different operating conditions. The Cu-hs exhibited high selectivity for Hg0 against H2O and SO2, which is advantageous for real applications in industrial flue gas. The Hg0 adsorption capacity of Cu-hs reached 3743 g/m3, about 14 times higher than the 243 g/m3 of Cordierite-hs. The excellent Hg0 adsorption performance of Cu-hs was attributed to the high affinity of the selenium in Cu2Se for mercury, the homogeneous distribution of Cu2Se, and the superior fluid characteristics of the Cu foam substrate. The adsorption performance of the spent Cu-hs could be effectively recovered by HCl solution leaching and subsequent reselenization. The utilization of recyclable Cu-hs provides a cost-effective and environmentally friendly method for removing mercury from industrial flue gas.