Recently, metal-organic frameworks (MOFs) have been investigated as potential materials for CO2 capture and light hydrocarbon storage/separation due to their high porosity, large surface area, and tunable skeleton structures. In this work, the six cobalt-based MOFs 1-6 were successfully synthesized under solvothermal conditions by a mixed-ligand strategy. 1 and 2 have the same framework structure with a topology of {4(2).5}(2){4(4).5(10).6(7).7(6).8}, while the structures of the 3-6 frameworks are the same with a topology of {4(2).5}(2){4(4).5(10).6(9).7(4).8}. The adsorption properties of these MOFs for CO2 and C-2 hydrocarbons were then investigated, and the effect of the functional groups was discussed. The results revealed that the introduction of amino and bromo groups could effectively strengthen the adsorption performance.