An Efficient Anti-poisoning Catalyst against SOx, NOx, and POx: P, N-Doped Carbon for Oxygen Reduction in Acidic Media

Electrocatalysts are readily poisoned during the catalysis of the oxygen reduction reaction (ORR); even air containing traces of SOx and/or NOx significantly decrease the activity and the durability of H-2-O-2 fuel cells. Now, a metal-free strategy is reported to develop an efficient anti-poisoning ORR catalyst, which involves the pyrolysis of PDAP-phytic acid super-molecular aggregate (PPSA). The pyrolyzed co-doped carbon acting as a metal-free electrocatalyst shows an enhanced activity for ORR in acidic medium, even under poisoning conditions (SOx, NOx, and POx). Moreover, P-doping also changes the ORR pathway by yielding less than 4% of H2O2, indicating a four-electron pathway whereas more than >20% of H2O2 was recorded for N-doped carbon synthesized from PDAP.