Catalytic oxidation of Hg 0 to HgO is an efficient way to remove Hg 0 from coal-fired flue gas. The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg 0 oxidation efficiency. Therefore, in the present work, wood vessels were used as sacrificial template to obtain Co 3 O 4 with ordered pore structure. SEM and BET results show that, when the mass concentrations of Co(NO 3 ) 2 ·6H 2 O was 20%, the obtained catalyst (Co 3 O 4 [20%Co(NO 3 ) 2 ]) possesses better pore structure and higher surface area. It will expose more available surface active sites and lower the mass transfer resistance. Furthermore, XPS results prove that Co 3 O 4 [20%Co(NO 3 ) 2 ] has the highest ratio of chemisorbed oxygen which plays an important role in Hg 0 oxidation process. These results lead to a better Hg 0 oxidation efficiency of Co 3 O 4 [20%Co(NO 3 ) 2 ], which is about 90% in the temperature range of 200 to 350 °C. Furthermore, Co 3 O 4 [20%Co(NO 3 ) 2 ] has a stable catalytic activity, and its Hg 0 oxidation efficiency maintains above 90% at 250 °C even after 90 h test. A probable reaction mechanism is deduced by the XPS results of the fresh, used and regenerated catalyst of Co 3 O 4 [20%Co(NO 3 ) 2 ]. Chemisorbed oxygen can react with Hg 0 forming HgO with the reduction of Co 3+ to Co 2+ . And lattice oxygen and gaseous oxygen can supplement the consumption of chemisorbed oxygen to oxidize Co 2+ to Co 3+ .