| Abstract
| - In part I of this paper, a model was proposed to (i) describe the gasification of a spherical carbon blackparticle by ammonia at high temperature and (ii) explain the activity for the O2 electroreduction of catalystsbased on Fe and carbon heat-treated in NH3. In this second part, such catalysts, heat-treated for various timesin ammonia, are characterized by electron microscopy, Raman spectroscopy, and time-of-flight secondaryion mass spectrometry (ToF-SIMS). Electron microscopy shows an average particle diameter of 38 nm forthe pristine furnace black, decreasing to 28 nm after the carbon powder loses 90% of its mass. This agreeswith model prediction. Raman spectroscopy shows that the experimental width at half-maximum of both thegraphitic peak (∼1595−1600 cm-1) and the disorder and graphitic-edge peak (∼1345−1355 cm-1) constantlydecreases with increasing weight loss. It is found that the width at half-maximum of these peaks correlateswith the fraction of disordered carbon phase calculated by the model. Last, changes of the ToF-SIMS totaland Fe+ signals upon gasification of the carbon black also support the model.
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