Fe, Cu bimetallic precursor-driven quaternary active sites boost oxygen reduction / evolution reaction bifunctional catalysts.

Searching for catalysts exhibiting durable, highly active and low-cost oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) poses challenges in developing cathodes for rechargeable metal-air batteries. In this work, we have prepared a novel electrocatalyst utilizing a Fe-Cu bimetallic pyridine-nitrogen coordination precursor, characterized by Cu/Fe 3 O 4 /Fe-N x /Cu-N x quaternary active sites. The obtained FeCu-N-C@XC-72 catalyst shows good activity in terms of both ORR (E 1/2 = 0.889 V) and OER (E j = 10 = 1.540 V), which exceeds those of commercial 20 % Pt/C (ORR) and RuO 2 (OER) catalysts. The Zn-air battery (ZAB) using FeCu-N-C@XC-72 as the cathode achieves a peak power density of 190.8 mW cm−2, far superior to that of 20 % Pt/C-based ZAB (93.7 mW cm−2). Notably, the devised FeCu-N-C@XC-72 has an outstanding durability of more than 360 h in a rechargeable ZAB. In conclusion, the FeCu-N-C@XC-72 electrocatalyst exhibits excellent potential for practical applications in energy storage systems, offering a promising solution for cathode development in Zn-air batteries. [Display omitted] • Introduction of iron and copper bimetallics using pyridinic-N as precursor. • Cu/Fe 3 O 4 /Fe-N x /Cu-N x quaternary active sites synergy. • FeCu-N-C@XC-72 has excellent ORR and OER performance. • The Zinc-air batteries have high capacity and excellent stability. [ABSTRACT FROM AUTHOR]