Efficient trifunctional electrocatalysts with iron single atoms electronically coupled with adjacent ruthenium nanoclusters for zinc-air battery-powered water splitting

Design and engineering of high-performance electrocatalysts is of significance for the development of integrated electrochemical energy technologies. Herein, N-doped carbon aerogels doped with Fe single atoms and adjacent Ru nanoclusters are prepared by two-step pyrolysis of a biomass hydrogel precursor. The obtained NCA/FeRu composites show an exceptional trifunctional activity towards the oxygen reduction reaction (ORR, half-wave potential +0.92 V), oxygen evolution reaction (OER, +275 mV overpotential at 10 mA cm −2 ) and hydrogel evolution reaction (HER, −7 mV overpotential at 10 mA cm −2 ), markedly better than those of relevant catalysts reported in the literature. First-principles calculations show that the Ru nanoclusters facilitate the *OH desorption for ORR and the formation of O−O bonds for OER on the FeN 4 sites, and the Ru clusters are primarily responsible for the high HER activity. Such a unique property can be exploited for the development of an integrated device for zinc-air battery-powered water splitting. • FeN 4 moieties with adjacent Ru nanoclusters on carbon aerogels by two-step pyrolysis. • Electronic interactions between FeN 4 and Ru nanoclusters. • Trifunctional electrocatalytic performance towards ORR, OER, and HER. • FeN 4 responsible for ORR and OER, while Ru for HER. • High performance in Zn-air battery-powered water splitting.