Yttrium Oxide Nanoclusters Boosted Fe-N₄ and Fe₄N Electrocatalyst for Future Zinc-Air Battery

Atomically distributed transition metal coordinated with nitrogen is considered as a class of promising oxygen reduction reaction (ORR) catalyst. However, the challenge of ineffective distribution of Fe-N-x active sites have been long existing, leading to low active site density and unstable performance, which needs be overcome for next generation ORR electrocatalysts. Herein, yttrium (Y) is introduced into atomically dispersed iron (Fe) nitrogen co-doped carbon materials to integrate nanoparticles, nanoclusters, and atomic sites, which endow the Fe-N-4-Y2O3 and Fe4N0.94-Y2O3 (FeY-NC) with outstanding ORR activity. The FeY-NC achieves half-wave potential of 0.926 and 0.809 V in alkaline and acidic condition, respectively. The kinetics current density at 0.9 V in alkaline condition is 31.2 mA cm(-2), which is 7.8 times of Fe-NC and 32.4 times of Pt/C. This outstanding activity of FeY-NC is enabled by the generated atomic FeN4 and Fe4N nanoparticles dual active-sites, and further the synergistic effect between the Fe-N-x/Fe4N0.94 with Y2O3 nanoclusters are loaded on nitrogen-doped carbon (NC) network. The superior performance of FeY-NC is demonstrated in a primary Zinc-air battery, deliver a peak power density of 233 mW cm(-2).