Highly graphitized carbon particles

In the electrodes for PAFC, the Vulcan XC-72 carbon black is most widely used catalyst support material [95]. The oxidation of Vulcan carbon black in the presence of phosphoric acid at 191 °C showed that the disordered central part of carbon particles was oxidized while the outer crystalline part remained intact [96]. Among the attempts to improve the oxidation resistance of Vulcan carbon black, the most widely used method is the heat treatment which increases the level of graphitization on the carbon surface [97]. The heat treatment of Vulcan carbon black at the temperature of 2200 °C which reduced the surface area of Vulcan from 240 to 80 m /g improved oxidation resistance more than twofold [98, 99]. Other highly graphitic carbon materials such as CNT [100] and graphene [101] have been used as support materials because of their high surface area and electrical conductivity. When selecting the carbonsupport material, the oxidation resistance is the critical property for carbon supports to enhance the durability of HT-PEMFC MEAs however, the surface area, shape, and size of support material should also be considered to achieve the desired dispersion of Pt particles as well as the pore structure within the catalyst layer. 

The wood is simply carbonised at relatively low temperatures in a restricted air supply to form an amorphous, quasi-graphitic carbon of very fine particle size. Although of reasonably high purity, it is the enormous surface area per unit mass of the charcoal which makes it very adsorbent to water vapour, and this property is conferred to the black powder mix, as Roger Bacon would have soon realised. 

---