A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä

Acidic and Alkaline pH Controlled Oxygen Reduction Reaction Pathway over Co-N4C Catalyst




TekijätMahapatra, Bikash K.; Barman, Pranjit; Panigrahi, Dipti R.; Kochrekar, Sachin; Paul, Bappi; Panghal, Abhishek; Kumar U, Anil; Dhavale, Vishal M.; Gupta, Mukul; Kumar, Deepak; Kumar, Vijay; Singh, Santosh K.

KustantajaWILEY-V C H VERLAG GMBH

KustannuspaikkaWEINHEIM

Julkaisuvuosi2024

JournalSmall

Tietokannassa oleva lehden nimiSMALL

Lehden akronyymiSMALL

Artikkelin numero2405530

Sivujen määrä12

ISSN1613-6810

eISSN1613-6829

DOIhttps://doi.org/10.1002/smll.202405530

Verkko-osoitehttps://doi.org/10.1002/smll.202405530


Tiivistelmä

Enhanced oxygen reduction reaction (ORR) kinetics and selectivity are crucial to advance energy technologies like fuel cells and metal-air batteries. Single-atom catalysts (SACs) with M-N-4/C structure have been recognized to be highly effective for ORR. However, the lack of a comprehensive understanding of the mechanistic differences in the activity under acidic and alkaline environments is limiting the full potential of the energy devices. Here, a porous SAC is synthesized where a cobalt atom is coordinated with doped nitrogen in a graphene framework (pCo-N4C). The resulting pCo-N4C catalyst demonstrates a direct 4e- ORR process and exhibits kinetics comparable to the state-of-the-art (Pt/C) catalyst. Its higher activity in an acidic electrolyte is attributed to the tuned porosity-induced hydrophobicity. However, the pCo-N4C catalyst displays a difference in ORR activity in 0.1 m HClO4 and 0.1 m KOH, with onset potentials of 0.82 V and 0.91 V versus RHE, respectively. This notable activity difference in acidic and alkaline media is due to the protonation of coordinated nitrogen, restricted proton coupled electron transfer (PCET) at the electrode/electrolyte interface. The effect of pH over the catalytic activity is further verified by Ab-initio molecular dynamics (AIMD) simulations using density functional theory (DFT) calculations.


Julkaisussa olevat rahoitustiedot
B.K.M., P.B., D.R.P., and S.K.S. acknowledge financial support from Shiv Nadar Institution of Eminence (SNIoE), India. S.K.S. acknowledges DST-SERB, India, for providing a financial grant (Grant No.: SRG/2022/000223). V.M.D. is thankful for the financial support of the SERB-CRG (CRG/2021/004395). The calculations have been performed on the high-performance computing facility Magus and Magus02 of SNIoE. The authors acknowledge Geeta Pandurang Kharabe, Sreekumar Kurungot, (CSIR-NCL, Pune) for facilitating the HAADF STEM and Aloke Kanjilal (Department of Physics, SNIoE) for facilitating the XAS analysis. D.K. acknowledges DST-SERB, India, for providing financial support (Grant No. CRG/2020/ 003882).


Last updated on 2025-27-01 at 19:59