Effective Homogeneous Catalysis of Electrochemical Reduction of Nitrous Oxide to Dinitrogen at Rhenium Carbonyl Catalysts

We show that reduced rhenium bipyridyl carbonyl complexes are stable and selective catalysts for deoxygenation of nitrous oxide (N2O) in organic media in the presence of water. Mechanistic studies indicate that the Re complex is initially reduced to produce the activated species. N2O then binds to labile position at the reduced metal and the resulting adduct is further reduced to trigger N-O bond breaking and release of N2. Proton donors are beneficial to enhance the catalytic rate and to reduce the energy required to generate potential limiting intermediate. These results open directions for N-O bond activation.