Boosting oxygen reduction with coexistence of single-atomic Fe and Cu sites decorated nitrogen-doped porous carbon

Rational design of iron-nitrogen-carbon (Fe-N-C) oxygen reduction reaction (ORR) catalysts simultaneously increasing the intrinsic activity and density of active site remains a huge challenge. Herein the coexistence of single-atomic Fe and Cu sites decorated nitrogen-doped porous carbon has been successfully fabricated by hy-drothermal synthesis of Fe, Cu co-doped ZIF-8 in the presence of Fe and Cu foam with subsequent NH3 pyrolysis. The X-ray absorption spectra confirmed the atomically dispersed Fe and Cu species with Fe-N4 and Cu-N4 co -ordination structures in the resultant FeCu SACs/NC catalyst. Meanwhile, the introduction of Cu has been experimentally and theoretically demonstrated to modulate the electronic structure of Fe active sites during the desorption of *OH intermediate process, as well as increase the density of Fe active sites, thereby effectively enhancing the intrinsic activity and selectivity toward the ORR.

Automated summary

In this study, nitrogen-doped porous carbon with coexisting single-atomic Fe and Cu sites was successfully fabricated, leading to an increase in the intrinsic activity and density of active sites for the oxygen reduction reaction. Experimental and theoretical results showed that the introduction of Cu can modulate the electronic structure of Fe active sites and increase the density of active sites, thereby enhancing the activity and selectivity of the oxygen reduction reaction.