Three Dimensional Macroporous Oxygen-Deficient TiO2-x Supported N, P, Co-tridoped Carbon as Efficient Oxygen Reduction Electrocatalyst

Graphical Electrocatalysis : This work is about the development of the 3DOM Co/NPC@TiO 2-x ORR electrocatalyst. The unique TiO 2-x -based 3DOM structure and the synergistic between N, P co-doping and Co-decoration contribute to improve the ORR catalytic activity and stability. The proposed electrocatalyst exhibits an outstanding half-wave potential of 0.86 V in alkaline electrolyte. The resulting primary and flexible zinc-air batteries also deliver considerable performance. Developing efficient and durable electrocatalysts of oxygen reduction reaction (ORR) is critical for high-performance air cathodes. Herein, a novel three-dimensionally ordered macroporous oxygen-deficient TiO 2 framework embedded with N, P and Co-tridoped carbon (3DOM Co/NPC@TiO 2-x ) is elaborately designed for ORR. This unique structure offers a high surface area, good mass transfer, excellent electronic conductivity, and stability. Moreover, the experimental and theoretical studies reveal that the synergistic effect of N, P co-doping and Co-decoration is indispensable to promote the ORR performance, yielding high O 2 adsorption energy and lowering the reaction barriers simultaneously. Accordingly, the ORR catalytic activity and stability of the proposed electrocatalyst are better than Pt/C in alkaline media. The resulting primary zinc-air battery delivers a high open-circuit voltage (1.50 V) and specific capacity (820 Wh kg −1 ) at 20 mA cm −2 . This strategy, combining macroporous oxygen-deficient oxide support with binary heteroatom doping, provides a new perspective for exploiting efficacious ORR electrocatalysts.