Abstract
Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have emerged as one of the most promising platinum-group metal (PGM)-free cathode catalysts for oxygen reduction reaction (ORR). Among the various approaches to enhance the ORR performance of the catalysts, increasing the density of accessible active sites is of paramount importance. Thus, nitrogen-rich support with abundant porosity can be very propitious. Herein, we report a highly porous polypyrrole (PPy) hydrogel as a versatile support for the facile design of a Co-N-C electrocatalyst for ORR. The resulting Co-N-C catalyst with abundant micro- and mesoporous combinations demonstrates a half-wave potential (E1/2) of 0.825 V vs reversible hydrogen electrode (RHE) in O2-saturated 0.1M KOH with just 2.1 wt % Co content. The ORR performance reduces only 11 mV (E1/2) after 5000 cycles of accelerated durability test (ADT), portraying its excellent stability. The catalyst retains ≈83% of its original current during a short-term durability test at 0.8 V vs RHE for 25 h. Furthermore, the catalyst shows electron transfer approaching ≈4 with low H2O2 yield in the potential range 0.5-0.9 V vs RHE. This work provides a simple design strategy to synthesize M-N-C catalysts with increased accessible active site density and enhanced mass transport for ORR and other electrocatalytic applications.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.