Transition metal oxide catalysts with high oxygen reduction activity and durability are highly desirable for use in fuel cells and metal-air batteries. Herein we report, for the first time, the oxygen reduction activity of hollow porous spinel AB₂O₄ microspheres, where A = Zn²⁺ and B = Mn³⁺ and/or Co³⁺ (i.e., ZnMn_xCo_2−xO₄). Among them, ZnMnCoO₄ (x = 1) microspheres exhibit the best oxygen reduction activity with a half-wave-potential only 50 mV lower than that of the Pt/C counterpart and an excellent durability in the alkaline solution. Importantly, the electronic transition of Co³⁺ ions from low-spin state in commercial Co₃O₄ catalyst to a mixed high-spin and low-spin state in ZnMnCoO₄ catalyst was found to weaken the Co³⁺-OH bond and facilitate the O²⁻/OH⁻ displacement. The density functional theory calculation substantiated that ZnMnCoO₄ displayed a more favorable binding energy with O₂ and oxygenated species, thereby enabling the fast reaction kinetics in the oxygen reduction reaction process.

具有高的氧还原活性和耐久性的过渡金属氧化物催化剂非常需要用于燃料电池和金属-空气电池中。在这里，我们首次报道了空心多孔尖晶石AB ₂ O ₄微球的氧还原活性，其中A = Zn ²⁺和B = Mn ³⁺和/或Co ³⁺（即ZnMn _x Co _2-x O ₄）。其中，ZnMnCoO ₄（x  = 1）微球显示出最佳的氧还原活性，其半波电位仅比Pt / C对应物低50 mV，并且在碱性溶液中具有出色的耐久性。重要的是，Co的电子过渡³⁺从低自旋态离子中的商业合作₃ Ò ₄催化剂的混合高自旋和低自旋状态中ZnMnCoO ₄催化剂中，削弱钴³⁺ -OH键并有利于ö ^{2- /} OH ^-移位。密度泛函理论计算证实，ZnMnCoO ₄与O ₂和含氧物质具有更好的结合能，从而在氧还原反应过程中具有快速的反应动力学。