An Isolated Zinc–Cobalt Atomic Pair for Highly Active and Durable Oxygen Reduction.

A competitive complexation strategy has been developed to construct a novel electrocatalyst with Zn‐Co atomic pairs coordinated on N doped carbon support (Zn/CoN‐C). Such architecture offers enhanced binding ability of O2, significantly elongates the O−O length (from 1.23 Å to 1.42 Å), and thus facilitates the cleavage of O−O bond, showing a theoretical overpotential of 0.335 V during ORR process. As a result, the Zn/CoN‐C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions with a half‐wave potential of 0.861 and 0.796 V respectively. The in situ XANES analysis suggests Co as the active center during the ORR. The assembled zinc–air battery with Zn/CoN‐C as cathode catalyst presents a maximum power density of 230 mW cm−2 along with excellent operation durability. The excellent catalytic activity in acid is also verified by H2/O2 fuel cell tests (peak power density of 705 mW cm−2). Discrete zinc/cobalt bimetallic sites were supported on N‐doped carbon (Zn/CoN‐C) through a competitive complexation stretegy. The as‐prepared Zn/CoN‐C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions, and the assembled Zn–air batteries and H2/O2 fuel cell show excellent power density and stability, which demonstrate suitability for practical applications. [ABSTRACT FROM AUTHOR]