Activity of carbon electrodes towards oxygen reduction in acid: A comparative study

The oxygen reduction reaction (ORR) has been investigated on a variety of carbon substrates, in acidic conditions, including glassy carbon (GC), edge plane pyrolytic graphite (EPPG), basal plane pyrolytic graphite (BPPG) and boron doped diamond (BDD). Along with these macro-sized substrates, a selection of carbon nanotube modified BPPG electrodes have also been examined. These include single walled (SWCNT), bamboo multi walled (B-MWCNT) and hollow multi walled (H-MWCNT) carbon nanotube modified BPPG. Low potential responses for ORR are found for substrates with large quantities of edge plane sites, namely EPPG and MWCNT modified BPPG. Along with being analytically significant in respect of gas sensing, these results have implications for proton exchange membrane (PEM) fuel cell catalyst supports.