Highly Active Fe/Pt Single-Atom Bifunctional Electrocatalysts on Biomass-Derived Carbon

The highly active bimetallic single-atom electrocatalysts are desirable for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) but remain challenging. Herein, Fe/Pt single-atom bifunctional electrocatalysts (Fe1Pt1/NC) are initially fabricated by nitrogen doping during the pyrolysis of porphyra and adsorbed urea at high temperature with subsequent nitrogen anchoring of Pt4+ in aqueous solution with the as-synthesized nitrogen-doped carbon. The as-synthesized Fe1Pt1/NC electrocatalysts have been intensively characterized by HAADF-STEM, XAFS, HRTEM, XRD, and Raman analysis. Particularly, the Fe1Pt1/NC presents excellent electrocatalytic activity toward HER, with relatively low overpotential of 27 mV at 10 mA cm–2 and small Tafel slopes of 28 mV dec–1. Furthermore, the Fe1Pt1/NC electrocatalyst possesses superior ORR activity with an onset potential of 1.04 V and half-wave potential of 0.91 V. This work provides a feasible way to synthesize electrocatalysts with abundant single-atom sites using renewable biomass as a precursor.