Formamide-soluble solid-state ZnO as Zn source for synthesizing FeCo-NC with ultrahigh oxygen reduction reaction activity

The high-cost synthesis of highly dispersed non-noble metal-nitrogen-carbon (MNC) electrocatalysts hinders their practical applications. Here, we have developed a cost/time-efficient synthesis method for MNC electrocatalysts with highly dispersed metal sites, using the commercially available cheap ZnO as the Zn source, reducing the cost of Zn usage by over 80%. Our specially chosen solvent formamide can react with ZnO and allow the formation of nano-sized ZnFeCo-Nx complexes uniformly distributed in the formamide-derived high-N-doped carbon substrate. Further annealing the ZnFeCo-N-C precursor will produce a highly dispersed FeCo-NC target product. Electrochemical measurements show that the prepared FeCo-NC is an excellent electrocatalyst for alkaline oxygen reduction reaction (ORR), rendering superior onset and half-wave potentials of 1.05 and 0.92 V, respectively. The Al-air battery assembled using this also shows a high specific power (204.9 mW cm −2 ) and a large specific capacity (552 mA h g −1 at 10 mA cm −2 ), exceeding those of the 20 wt% Pt/C catalyst. Our method may inspire the scalable and low-cost production of highly dispersed MNC electrocatalysts and their wide range of practical applications. Cost/time-efficient synthesis of highly dispersed M-N-C electrocatalysts was established using solid-state ZnO as new Zn source, rendering superior ORR ( E onset ∼ 1.05 V and E 1/2 ∼ 0.92 V) and Al-air battery performance.