Energetic MOF-derived Fe3C nanoparticles encased in N, S-codoped mesoporous pod‐like carbon nanotubes for efficient oxygen reduction reaction

Abstract

Rational design of advanced oxygen reduction reaction (ORR) catalysts is essential to improve the performance of energy conversion devices. However, it remains a grand challenge to construct hierarchically micro/meso/macroporous nanostructures, especially mesoporous transport channels in catalysts, to enhance the catalytic capability. Herein, motivated by the characteristic of energetic metal-organic frameworks (EMOFs) that produce an abundance of gases during high-temperature pyrolysis, we prepared a unique tetrazine-based EMOF-derived electrocatalyst (denoted as Fe3C@NSC-900) consisting of highly dispersed Fe3C nanoparticles and N, S-codoped mesoporous carbon nanotubes. The mesopore-dominated core-shell structure endows Fe3C@NSC-900 with excellent catalytic activity and efficient mass transfer. Thus, the optimal Fe3C@NSC-900 demonstrates a high half-wave potential of 0.922 V, and great stability in 0.1 M KOH, outperforming commercial Pt/C and most of reported ORR catalysts. For all we know, this work is the first application of tetrazine-based EMOF derivative for electrocatalytic ORR, and is expected to offer some constructive insights for potential of EMOF in new-generation catalyst design.