Development of copper sulfide functionalized CeO2 nanoparticle for strengthened removal of gaseous elemental mercury from flue gas

The development of effective sorbents is of great significance for realizing the immobilization of gaseous elemental mercury from coal-fired flue gas. Herein, CuS/CeO2 composite sorbent was synthesized by a simple precipitation method for the removal of elemental mercury from flue gas. The ability of CuS/CeO2 to capture mercury at different temperatures and different flue gas components (HCl, SO2, O2 and NO) were tested. It indicates that CuS/CeO2 exhibits excellent Hg0 removal performance both at 60-150 degrees C and in different flue gas components. Moreover, the equilibrium adsorption capacity of CuS/CeO2 was 32.304 mg g-1 at 120 degrees C, which was 59.8 times that of CuS/GCN and 190 times that of ZnS modified activated carbon. Density functional theory (DFT) calculations further verified that the synergistic relationship between defect oxygen and unsaturated sulfur sites on the surface promotes the Hg0 removal performance of CuS/CeO2. By virtue of these advantages, CuS/ CeO2 is a prodigious candidate for the effective mercury removal from various types of industrial flue gases. This work may open-up new approaches for the development of heavy metal sorbents through the inter-doping of metal sulfides with transition metal oxides to enhance surface active sites to tune the adsorption capacity.

Automated summary

In this study, CuS/CeO2 composite sorbent was synthesized and showed excellent performance in removing elemental mercury from coal-fired flue gas. The mechanism behind its high adsorption capacity was analyzed and verified. This work provides new approaches for the development of heavy metal sorbents.