Direct Ammonia Fuel Cells (DAFCs) are expected to be an effective alternative to hydrogen fuel cells due to the low cost and ease of storage and distribution of ammonia. However, current DAFC technology is greatly limited by the kinetically slow Ammonia Oxidation Reaction (AOR) at the anode. In this work, carbon-supported platinum-iridium catalysts were successfully synthesized. The platinum-iridium precursor was reduced on carbon by impregnation method. After loading PtIr cubes, the catalyst exhibited high AOR catalytic activity. The structure and composition of the catalysts were then characterized by transmission electron microscopy, x-ray diffraction and inductively coupled plasma spectroscopy mass spectrometry. The results on Rotating Disk Electrode (RDE) showed that the peak current of ammonia oxidation (216.6 mA/mg) of the as-prepared PtIr catalyst was 2.1 times higher than that of the commercial Pt/C catalyst (66.3 mA/mg). The synthesized catalyst was assembled with an anion-exchange membrane to fabricate an alkaline DAFC, reaching a peak power density of 128 mW/cm2.
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