A polypyrrole derived nitrogen doped porous carbon support for an atomically dispersed Mn electrocatalyst for the oxygen reduction reaction

Platinum group metal (PGM)-free catalysts are highly desirable for oxygen reduction reaction (ORR) in electrochemical energy conversion devices, towards large scale commercialization of this technology. Here, we report a facile design approach using polypyrrole (PPy) hydrogel to synthesize an efficient ORR electrocatalyst featuring atomically dispersed Mn coordinated to nitrogen on partially graphitic carbon (Mn-N-C). The Mn-N-C catalyst exhibited a half-wave potential of 0.82 V versus the reversible hydrogen electrode, along with a limiting current density of -4.68 mA cm(-2). The catalyst retains & AP;87% of its original current during a short term durability test for 50 hours. Furthermore, the electron transfer number and H2O2 yield for the catalyst approach 3.85-3.95 and 7.60-2.54% respectively in the potential range 0.4-0.8 V vs. RHE. The simplified approach can be used for the synthesis of other M-N-C catalysts for various electrochemical applications.