Ce-1-Co-3 catalyst prepared by template method has been proved to have a good Hg-0 removal efficiency due to its large surface area and plenty of surface active sites. However, the strong interaction between Ce and Co has a significant influence on physicochemical property and Hg-0 removal efficiency, and the interaction mechanism has not been thoroughly explained to date. To understand the interaction mechanism of Ce and Co, Ce-Co catalysts with different Ce/Co molar ratios were prepared by the template method. N-2 adsorption, XRD, TEM, HRTEM, XPS and H-2-TPR were used to investigate physicochemical properties of the catalysts. Catalysts with very different molar amounts of Ce and Co (like Ce-1-Co-6 and Ce-6-Co-1) had more lattice defects resulting in more surface active sites. But they had non-uniform mesoporous channels and a low BET surface area leading to a large mass transfer resistance. In contrast, similar molar amount of Ce and Co leaded to uniform mesoporous channels and a much larger BET surface area, but less surface active sites (like Ce-1-Co-1). Furthermore, high Ce concentration leaded to a high crystallinity of CeO2, a low specific surface area and a non-uniform pore structure due to the sintering of CeO2. And more Co introduction enhanced the redox properties at low temperature. For these reasons, Ce-1-Co-3 had the best Hg-0 oxidation efficiency and the widest temperature window, which was more than 90% in the temperature range of 150-400 degrees C.