Nonenzymatic glucose fuel cells with an anion exchange membrane as an electrolyte

Nonenzymatic glucose fuel cells were prepared by using a polymer electrolyte membrane and Pt-based metal catalysts. A fuel cell with a cation exchange membrane (CEM), which is often used for conventional polymer electrolyte fuel cells, shows an open circuit voltage (OCV) of 0.86 V and a maximum power density (P_max) of 1.5 mW cm^?2 with 0.5 M d-glucose and humidified O₂ at room temperature. The performance significantly increased to show an OCV of 0.97 V and P_max of 20 mW cm^?2 with 0.5 M d-glucose in 0.5 M KOH solution when the electrolyte membrane was changed from a CEM to an anion exchange membrane (AEM). This is due to the superior catalytic activity for both glucose oxidation and oxygen reduction in alkaline medium than in acidic medium. The anodic reaction of the fuel cell can be estimated to be the oxidation of glucose to gluconic acid via a two-electron process under these experimental conditions. The crossover of glucose through an electrolyte membrane was negligibly small compared with methanol and may not represent a serious technical problem due to the cross-reaction.