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Compared to extensively studied oxygen reduction reaction (ORR) catalysis in alkaline media, development of highly active and stable nonprecious metal catalysts (NPMCs) to replace Pt in acidic electrolytes remains grand challenges. Among currently studied catalysts, the Fe-N-C formulation holds the greatest promise for the ORR in acid. Here, we report a new highly active and stable Fe-N-C catalyst featured with well-dispersed atomic Fe in porous carbon matrix, which was prepared through one single thermal conversion from Fe-doped ZIF-8, a metal-organic framework (MOF) containing Zn 2+ and well-defined Fe-N4 coordination. Unlike other Fe-N-C catalyst preparation, no additional tedious post-treatments such as acid leaching and the second heating treatment are required in this work. Notably, an O2-free environment for preparing the Fedoped ZIF-8 precursor is found to be crucial for yielding uniform Fe distribution into highly porous N-doped carbon matrix. The resulting new Fe-N-C catalyst exhibited exceptionally improved ORR

Understanding the Cu-catalyzed electrochemical CO 2 reduction reaction (CO 2 RR) under ambient conditions is both fundamentally interesting and technologically important for selective CO 2 RR to hydrocarbons. Current Cu catalysts studied for the CO 2 RR can show high activity but tend to yield a mixture of different hydrocarbons, posing a serious challenge on using any of these catalysts for selective CO 2 RR. Here, we report a new perovskite-type copper(I) nitride (Cu 3 N) nanocube (NC) catalyst for selective CO 2 RR. The 25 nm Cu 3 N NCs show high CO 2 RR selectivity and stability to ethylene (C 2 H 4 ) at −1.6 V (vs reversible hydrogen electrode (RHE)) with the Faradaic efficiency of 60%, mass activity of 34 A/g, and C 2 H 4 /CH 4 molar ratio of >2000. More detailed electrochemical characterization, X-ray photon spectroscopy, and density functional theory calculations suggest that the high CO 2 RR selectivity is likely a result of (100) Cu(I) stabilization by the Cu 3 N structure, which favors CO−CHO coupling on the (100) Cu 3 N surface, leading to selective formation of C 2 H 4 . Our study presents a good example of utilizing metal nitrides as highly efficient nanocatalysts for selective CO 2 RR to hydrocarbons that will be important for sustainable chemistry/energy applications.