Glucose Fueled Alkaline Fuel Cell

Abstract

The electrical behavior of a room temperature membraneless Alkaline Fuel Cell, with incorporated platinum particles in the anode and fueled with glucose, is reported. The Open Circuit Voltage, at different initial glucose concentrations was measured. Changes on the glucose concentration with time were monitored with the dinitrosalicylic acid method. Qualitative Thin Layer Chromatography demonstrates that the electrodes induce polymerization of the glucose. The electrical yield of the system was measured with different external resistors. The Open Circuit Voltage reaches a saturation value of 0.78±0.03 V at [glu]0 > 0.67 M. During four hours in Open Circuit conditions, there is a 20% drop in the concentration of reducing sugar in the fuel cell. Thin Layer Chromatography experiments show that the electrodes catalyze non-electrochemical glucose polymerization reactions. Assuming that the glucose is oxidized to gluconic acid, the electrical yield of the system is around 5%.

Viologen Catalysts for a Direct Carbohydrate Fuel Cell

“…This is clearly shown with methyl-␣-D-glucoside, sucrose, and the second glucose unit in maltose, lactose, and cellobiose that do not undergo reaction. Decreasing reactivity of glucose in alkaline fuel cells was previously observed 12 and attributed to ͑i͒ a Cannazzarotype reaction ͑2 glucose → sorbitol + glucoronic acid͒, ͑ii͒ polymerization of glucose, and ͑iii͒ glucose being altered at the C 1 position by an unidentified reaction by-product. These possibilities could also limit the reactions observed here and lower the overall oxidation efficiency.…”

“…The presence of free radicals and formation of reactive oxygen-containing intermediates could contribute to uncontrollable reaction pathways that lead to irreproducibility. In addition, glucose inactivation by polymerization was previously reported in alkaline glucose fuel cells 12 that could also influence reproducibility.…”

“…A potentially more energy-efficient process is directly extracting energy from biomass as electricity and three general approaches are being explored. Metal catalysts such as platinum liberate electrons from glucose, [9][10][11][12] but platinum is expensive for large-scale use and conversion rates are low and currently uncompetitive. Direct enzymatic oxidation of glucose ͑glucose → gluconic acid͒ is being explored for powering implanted medical devices [13][14][15][16][17][18][19] but this inefficient process utilizes only 2 of the 24 electrons available from glucose.…”