fuel cellsmetal-air batteriesoxygen evolution reactionoxygen reduction reactionporous perovskite-type oxides
J.Yu and R.Ran contributed equally to this work.M.Ni thanks the funding sup-portResearch Grant Council,Univer-sity Grants Committee,Hong Kong SAR.Z.P.Shao acknowledges the financial support from National NatuNational Key Research and Development Program of China
PolyU 152214/17E218781582018YFB0905402
2020