A novel nano-sized Co 3 O 4 @C catalyst derived from Co-MOF template for efficient Hg 0 removal at low temperatures with outstanding SO 2 resistance

Co 3 O 4 is a promising Hg 0 removal catalyst for industrial application. Operating temperature and low sulfur resistance are two of the main problems that hinder its industrial application in Hg 0 removal. Herein, a metal-organic framework (Co-BDC) was introduced as a sacrificial template to obtain the catalyst nano-sized Co 3 O 4 @C by calcination. Part of the organic ligands is carbonized during the calcination. Carbon wrapped Co 3 O 4 and reduced metal agglomeration. The optimal Hg 0 removal temperature of the existing cobalt oxide catalysts was always around 150 °C, but H 2 -TPR showed that the oxygen atoms on the Co 3 O 4 @C were more active than those on Co 3 O 4 , causing the Hg 0 removal temperature window of Co 3 O 4 @C to shift to lower temperatures. The Hg 0 removal efficiency of Co 3 O 4 @C could reach almost 100% even at 25 °C. In the meanwhile, Co 3 O 4 @C also showed a strong SO 2 resistance at ambient temperature. Experimental results and characterization proved that SO 2 did not compete with Hg 0 on the surface of Co 3 O 4 at low temperatures. On the contrary, it participated in the oxidation of Hg 0 . This is a great improvement for Co 3 O 4 catalyst in Hg 0 removal. It reduces the restrictions on the application of Co 3 O 4 in Hg 0 removal. Co 3 O 4 @C shows considerable potential as an Hg 0 removal catalyst.