Abstract
Non-precious metal electrocatalysts(such as Fe-N-C materials)for the oxygen(O2)reduction reaction demand a high catalyst loading in fuel cell devices to achieve workable performance.However,the extremely low solubility of O2 in water creates severe mass transport resistance in the thick catalyst layer of Fe-N-C catalysts.Here,we introduce silicalite-1 nanocrystals with hydrophobic cavities as sustainable O2 reservoirs to overcome the mass transport issue of Fe-N-C catalysts.The extra O2 supply to the adjacent catalysts significantly alleviated the negative effects of the severe mass transport resistance.The hybrid catalyst(Fe-N-C@silicalite-1)achieved a higher limiting current density than Fe-N-C in the half-cell test.In the H2-O2 and H2-air proton exchange membrane fuel cells,Fe-N-C@silicalite-1 exhibited a 16.3％and 20.2％increase in peak power density compared with Fe-N-C,respectively.The O2-concentrating additive provides an effective approach for improving the mass transport imposed by the low solubility of O2 in water.
维普
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