Zeolitic Imidazolate Framework-Derived Copper Single Atom Anchored on Nitrogen-Doped Porous Carbon as a Highly Efficient Electrocatalyst for the Oxygen Reduction Reaction toward Zn–Air Battery

Here, copper single atoms anchored on nitrogen-doped porouscarbon (Cu-N/PC) derived from zeolitic imidazolate frameworks (ZIFs) as ahighly efficient electrocatalyst for the oxygen reduction reaction (ORR) weredemonstrated. Specifically, as a nitrogen-rich bridge molecule, tubular g-C3N4(TCN) can trap free Cu ions through the electrostatic interaction in the initialstage. Then, Cu-ion-doped TCN can be used to regulate the content of copperand nitrogen doping, the electronic structure, as well as the specific surface areaand pore diameter of Cu-N/PC. As a result, the high density of exposed Cu-N4active sites and the high level of porosity in Cu-N/PC may significantly enhancethe ORR activity with a more positive onset potential (E0= 0.97 V versusreversible hydrogen electrode (RHE)) and half-wave potential (E1/2= 0.88 V)than the commercially available Pt/C catalyst (E0= 0.94 V,E1/2= 0.85 V).Furthermore, the homemade Zn-air battery (ZAB) equipped with Cu-N/PC isable to deliver excellent performance, including a peak power density of 215.8 mW cm-2and a specific capacity of 704.9 mAh g-1based on Zn anode, outperforming the Pt/C catalyst. Thefinding highlights a new guideline for constructing Cu-N/PC catalyst witha well-designed structure and superior property for advanced fuel cell cathode materials.