Direct oxidation of ammonia borane as an alternative fuel at nanoporous Au

Ammonia borane (AB) is a chemically stable, non-toxic solid with a high hydrogen content (19.5 wt. %) which is easily transported and is highly soluble in water. It has been shown that hydrogen can be released from AB via catalytic hydrolysis or thermal decomposition. It can thermally decompose in the temperature range 340-410 K to liberate 2.2 mol H2 per mol of ammonia borane which is equivalent to a hydrogen storage density of 14.3 wt. %. The high energy density coupled with the moderate decomposition temperature make ammonia borane an attractive hydrogen source for fuel cells. However, if the direct electrochemical oxidation of ammonia borane occurs in a fuel cell a more negative potential and greater power can be obtained than indirectly using hydrogen as the fuel. A novel direct AB fuel cell (DABFC) can be proposed by combining the anodic oxidation of AB given be Eqn. 1 and cathodic reduction of oxygen (Eqn. 2). NH3BH3 + 6OH- = BO2- + 4NH4++ 4H2O + 6e E0 = -1.216 V vs SHE (1) 1.5O2 + 3H2O + 6e = 6OH- E0 = 0.40V vs SHE (2) DABFC: NH3BH3 + 1.5O2 = BO2- + NH4+ + H2O E0 = 1.616 V (3