A simple and high efficient direct borohydride fuel cell with MnO2-catalyzed cathode

A simple direct borohydride fuel cell (DBFC) was constructed by use of an MnO2-catalyzed air cathode and an Au-catalyzed anode. It is found that the MnO2 cathode not only exhibits considerable electrocatalytic activity for oxygen reduction in the BH4- solutions, but also shows indiscernible catalytic activities for the electrooxidation and chemical hydrolysis of BH4- ions. As a result, these DBFC cells can avoid not only the performance degradation of the cathode arising from “BH4- crossover” but also do not need to use expensive ion exchange membranes and Pt catalyst in the cathode. Based on this new configuration of DBFC, we used nanosized Au particles as an anodic electrocatalyst to avoid the chemical hydrolysis of BH4- ions, thereby to realize the complete electrochemical oxidation of BH4- ions.