Nitrogen doping of graphene nanoflakes by thermal plasma as catalyst for oxygen reduction in Proton Exchange Membrane fuel cells

Proton Exchange Membrane fuel cells (PEMFCs) have two major hurdles to overcome before they may be commercially viable: cost and operating life. Platinum (Pt) catalyst represents the bulk of the PEMFC cost and is in finite supply, but functionalized carbon nanomaterials have been identified as potential replacements for Pt cathode catalyst. This work´s objective is to produce graphene nanoflakes (GNFs) and dope them with nitrogen in pyridinic sites through a second treatment step. An inductively-coupled thermal plasma (ICP) is used to dissociate methane at very high temperatures, with GNF nucleation commencing shortly after by way of rapid quenching. In a post-treatment, nitrogen doping occurs by manipulating plasma conditions and nitrogen precursor selection. Nitrogen doping up to 33.4 at.% has been demonstrated which, to our knowledge, more than doubles the largest reported amount.