Ethanol Fuel Cell
A new catalyst could make the technology usable in portable electronics.
Source: “Ternary Pt/Rh/SnO2 Electrocatalysts for Oxidizing Ethanol to CO2”
Radoslav Adzic et al.
Nature Materials 8: 325-330
Results: A new catalyst efficiently breaks the strong carbon-carbon bond at the center of ethanol molecules, converting ethanol to carbon dioxide in a process that releases protons and electrons. It generates electrical currents 100 times greater than those produced with other catalysts that oxidize ethanol.
Why it matters: Ethanol-powered fuel cells based on the catalyst could open the way for portable electronics that can be refueled faster than battery-powered devices can be recharged. The technology would also be safer than portable fuel cells that use toxic methanol. Previous catalysts used to free electrons from ethanol were inefficient: either they used a great deal of energy to break the carbon-carbon bond or they broke only the molecule’s weaker bonds, releasing just a few electrons per molecule. The new catalyst efficiently frees 12 electrons per molecule without requiring much energy.
Methods: To make the catalyst, researchers at Brookhaven National Laboratory in New York deposited tiny clusters of platinum and rhodium on tin oxide nanoparticles. Rhodium had been shown to break bonds between carbon atoms, but only at high temperatures–200 to 300 °C. Combining the rhodium and platinum with tin oxide allowed it to break these bonds at room temperature, making the catalyst more practical for portable fuel cells.
Next steps: The catalyst will be incorporated into fuel cells to determine whether the current produced can be increased from the 7.5 milliamps per square centimeter seen in initial tests to the hundreds of milliamps needed for most applications.