Cobalt-containing ZIF-derived catalysts for Zn–air batteries

Abstract

Zinc–air batteries (ZABs) are safe, environmentally friendly and stable energy storage devices. However, the two important electrochemical reactions (ORR and OER) in ZABs have high reaction barriers, and thus require the help of a catalyst. At present, the efficient commercial bifunctional catalyst (Pt + RuO₂) has some drawbacks such as high price and poor stability. Thus, it is extremely important to find efficient and inexpensive bifunctional electrocatalysts for ZABs. In this case, zeolitic imidazolate frameworks (ZIFs) are emerging functional materials with highly ordered pore structures and extremely strong catalytic activity, which have attracted much attention due to their high specific surface area, tunable pore size, and structural diversity. Especially, cobalt-containing catalysts derived from ZIFs containing cobalt have excellent bifunctional electrocatalytic properties. Cobalt-containing ZIFs with different amounts of metal possess different synergistic effects and active sites. This review summarizes the preparation and modification methods and active sources of ZIF-derived catalysts containing different amounts of cobalt. Furthermore, we summarized the application of ZIF-derived catalysts containing different amounts of cobalt in ORR and OER. Finally, we briefly discussed the development prospects of ZIF-derived catalysts containing different amounts of cobalt in the field of oxygen electrocatalysis and ZABs.