High Power Density of a Hydrogen Peroxide Fuel Cell Using Cobalt Chlorin Complex Supported on Carbon Nanotubes as a Noncorrosive Anode

Hydrogen peroxide fuel cells (HPFCs) have attracted much attention due to their simple one-compartment structures and high availability under harsh conditions such as an anaerobic environment; however, catalysis improvement is strongly demanded for both anodes and cathodes in terms of activity and durability. Herein, we report the high catalytic activity of Co-II chlorin [Co-II(Ch)] for hydrogen peroxide (H2O2) oxidation with a low overpotential (0.21 V) compared to that of the Co-II phthalocyanine and Co-II porphyrin complexes, which have previously been reported as active anode catalysts. Linear sweep voltammograms and differential pulse voltammograms of the Co-II complexes ((CoL)-L-II) and the corresponding ligands clearly showed that the (CoL)-L-III species are the active species for H2O2 oxidation. Then, one-compartment HPFCs were constructed with Co-II(Ch) supported on multiwalled carbon nanotubes (CNTs) as the anode together with Fe-3(II)[Co-III(CN)(6)](2) supported on CNTs as the cathode. The maximum power density of the HPFCs reached 151 mu W cm(-2) with an open circuit potential of 0.33 V when the coverage of CNT surfaces with Co-II(Ch) exceeded similar to 60% at the anode.