The design and synthesis of a new porous organic polymer (POP) incorporated with cobalt carbonyl complexes through built-in bipyridinic coordination sites for hydrogen storage are described. A thermal activation process was developed to remove the ligated carbonyl and carbon dioxide in order to expose the cobalt atomically inside of porous structure. Various spectroscopic and physical characterization techniques were used to study the coordinated Co sites and the POP's surface property. Upon thermal activation, this new cobalt-containing POP showed improved hydrogen uptake capacity and isosteric heat of adsorption.