Theophylline-regulated pyrolysis synthesis of nitrogen-doped carbon nanotubes with iron-cobalt nanoparticles for greatly boosting oxygen reduction reaction

At present, construction of economical, efficient and stable electrocatalysts for oxygen reduction reaction (ORR) is critical to alleviate the energy shortage. Theophylline (THP) can be easily extracted from natural plants, whose nitrogen atoms can chelate with metal ions. With assistance of THP, FeCo alloy was confined in N-doped carbon nanotubes (FeCo/NCNTs-800) by one-step pyrolysis of a mixture of the metal precursors, g-C3N4 and THP. The resulting FeCo/NCNTs-800 showed a better ORR performance (onset potential, E-onset = 1.09 V; half-wave potential, E-1/2 = 0.87 V) than commercial Pt/C (50 wt%) in a 0.1 M KOH solution, with a limiting current density as high as -5.54 mA cm(-2). This work offers a feasible strategy for developing transitional bimetal-based carbon catalysts in alkaline fuel cells. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

Developing economical, efficient, and stable electrocatalysts for the oxygen reduction reaction (ORR) is crucial in alleviating the energy shortage. In this study, FeCo alloy was successfully confined in N-doped carbon nanotubes (FeCo/NCNTs-800) with the assistance of theophylline (THP), which can be easily extracted from natural plants. The resulting FeCo/NCNTs-800 catalyst exhibited superior ORR performance compared to commercial Pt/C (50 wt%) in an alkaline solution, providing a feasible strategy for the development of transition metal-based carbon catalysts in alkaline fuel cells.