Materials Science

3D Lowers T

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Science  04 Oct 2013:
Vol. 342, Issue 6154, pp. 15
DOI: 10.1126/science.342.6154.15-a

Most solid oxide fuel cells operate at temperatures above 800°C, necessitating robust supporting materials for insulation and rendering on/off cycling inefficient. Lower-temperature operation has tended to lead to a loss of catalytic activity. An et al. combined several approaches to create a cell that performs well at temperatures as low as 450°C. At the core is a three-dimensional (3D) membrane electrode assembly (MEA) structure, which increases the surface area for the catalytic reactions. On both the top and bottom surfaces, a layer of porous platinum was deposited, further enhancing the reaction area. The addition of yttria-doped ceria at the cathode interface of the MEA below the top platinum surface helped reduce activation losses by 35%. The open circuit voltage was measured to be close to the thermodynamic limit, showing electronic and chemical isolation of the cathode and anode. The work is still at an early stage, though, as the performance of the MEA dropped by about 30% during the first hour of operation, possibly due to changes in structure, but did not show further changes after another 2 hours of operation.

Nano Lett. 13, 4551 (2013).

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