Engineering Co‐N‐Cr Cross‐Interfacial Electron Bridges to Break Activity‐Stability Trade‐Off for Superdurable Bifunctional Single Atom Oxygen Electrocatalysts

Abstract

Atomically dispersed metal‐nitrogen‐carbon (M‐N‐C) catalysts have exhibited encouraging oxygen reduction reaction (ORR) activity. Nevertheless, the insufficient long‐term stability remains a widespread concern owing to the inevitable 2‐electron byproducts, H2O2. Here, we construct Co‐N‐Cr cross‐interfacial electron bridges (CIEBs) via the interfacial electronic coupling between Cr2O3 and Co‐N‐C, breaking the activity‐stability trade‐off. The partially occupied Cr 3d‐orbitals of Co‐N‐Cr CIEBs induce the electron rearrangement of CoN4 sites, lowering the Co‐OOH* antibonding orbital occupancy and accelerating the adsorption of intermediates. Consequently, the Co‐N‐Cr CIEBs suppress the two‐electron ORR process and approach the apex of Sabatier volcano plot for four‐electron pathway simultaneously. As a proof‐of‐concept, the Co‐N‐Cr CIEBs is synthesized by the molten salt template method, exhibiting dominant 4‐electron selectively and extremely low H2O2 yield confirmed by Damjanovic kinetic analysis. The Co‐N‐Cr CIEBs demonstrates impressive bifunctional oxygen catalytic activity (∆E=0.70 V) and breakthrough durability including 100% current retention after 10 h continuous operation and cycling performance over 1500 h for Zn‐air battery. The hybrid interfacial configuration and the understanding of the electronic coupling mechanism reported here could shed new light on the design of superdurable M‐N‐C catalysts.