Multi-functional hydrogen- and oxygen-capturing FeCo-N-C catalyst with improved hydrogenation of nitroarenes and ORR activity

Abstract

Hydrogen energy storage and transportation are critical issues that must be addressed to ensure the development of alternatives to fossil fuel energy in the future. Herein, the poly(Schiff base) strategy is used to explore the carbon substrate, which is enclosed with binary metal Fe and Co as precursors. After the calcination and acid treatment steps, one of the FeCo alloy, termed FeCoNC-1000A900, was assembled with porous carbon skeleton as a shell and enclosed with FeCo alloy as a core. The FeCoNC-1000A900 exhibits outstanding H2 capture properties from NaBH4/EtOH mixtures circumstance owing to its large average particle size of 45 nm and high specific surface area of 462.07 m2/g. Notably, the FeCoNC-1000A900 acquires bi-functional catalysis efficacy, one is for chemoselectivity in the hydrogenation of nitroarene substrates and shows a high turnover frequency in 690 h−1 within the overall conversion yield. The other one is the O2 capture performance toward the oxygen reduction reaction with the excellent onset potential of 0.89 V, the half-wave potential of 0.77 V, and limiting current density of − 5.56 mA cm−2, which are comparable to those of the commercial Pt/C catalyst. In addition, the Tafel slope of 79.6 mV dec−1 is lower than those for other catalysts. Consequently, the development of the novel FeCoNC-1000A900 catalyst has two functional applications.