A novel nano-sized Co3O4@C catalyst derived from Co-MOF template for efficient Hg0 removal at low temperatures with outstanding SO2 resistance

Abstract

Co3O4 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 removal. Herein, a metal-organic framework (Co-BDC) was introduced as a sacrificial template to obtain the catalyst nano-sized Co3O4@C by calcination. Part of the organic ligands carbonized during the calcination. Carbon wrapped Co3O4 and reduced metal agglomeration. The optimal Hg 0 removal temperature of the existing cobalt oxides catalysts was always around 150 ℃, but H2-TPR showed that the oxygen atoms on the Co3O4@C were more active than those on commercial Co3O4, causing the Hg 0 removal temperature window of Co3O4@C to shift to lower temperatures. The Hg 0 removal efficiency of Co3O4@C could reach almost 100% even at 25 ℃. In the meanwhile, Co3O4@C also showed a strong SO2 resistance at ambient temperature. Experimental results and characterization proved that SO2 did not compete with Hg 0 on the surface of Co3O4 at low temperatures. On the contrary, it participated in the oxidation of Hg 0 . This is a great improvement for Co3O4 catalyst in Hg 0 removal. It reduces the restrictions on the application of Co3O4 in Hg 0 removal. Co3O4@C shows considerable potential as an Hg 0 removal catalyst.