Non-noble bimetallic CuCo alloy nanoparticles (NPs) were successfully encapsulated in the pores of MIL-101 by using the double-solvent method combined with the overwhelming reduction approach. Compared with their monometallic counterparts, the bimetallic CuCo alloy NPs present much higher catalytic activity for hydrolytic dehydrogenation of ammonia borane (AB) to generate a stoichiometric amount of hydrogen at room temperature for chemical hydrogen storage. The synergistic effect between copper and cobalt species plays an important role for the improved performance in the catalytic hydrolysis of AB.