Tailoring Coordination and Pore Structure of MOF‐Derived Co Single‐Atom Catalysts Anchored on Graphene for Rechargeable Zinc–Air Batteries

Why It Matters

The breakthrough demonstrates how simultaneous pore and coordination engineering can dramatically improve catalyst efficiency, accelerating the commercialization of high‑performance zinc‑air batteries for grid‑scale energy storage.

Key Takeaways

• Polymer encapsulation creates mesoporous carbon framework.
• Wavy graphene tunes Co–N coordination symmetry.
• Defect-rich Co‑N3 sites boost oxygen reaction activity.
• Half‑wave potential reaches 0.90 V for ORR.
• ZAB delivers 190 mW cm⁻² power, 832 mAh g⁻¹ capacity.

Pulse Analysis

Single‑atom catalysts (SACs) have emerged as a promising class for electrocatalysis due to their maximized metal utilization and tunable active sites. However, most MOF‑derived SACs suffer from microporous carbon matrices that impede mass transport and exhibit planar coordination environments that limit intrinsic activity. Addressing these constraints requires a holistic design that simultaneously expands pore networks and tailors the electronic structure of the isolated metal atoms, a challenge that has hindered the deployment of SACs in high‑current energy devices.

The new dual‑strategy leverages polyvinylpyrrolidone (PVP) coating on Co/Zn zeolitic imidazolate framework precursors to induce controlled shrinkage during pyrolysis, generating uniform mesopores that facilitate oxygen diffusion. Concurrently, assembling the precursors on a wavy graphene oxide sheet introduces curvature‑induced strain, elongating Co‑N bonds and breaking symmetry to form Co‑N3 configurations rich in defects. This synergy yields a catalyst—CoSA@P‑NC/rGO—with superior bifunctional performance: a 0.90 V half‑wave potential for ORR and a 397 mV overpotential for OER at 10 mA cm⁻², metrics that rival or surpass many noble‑metal benchmarks.

When deployed as the cathode material in rechargeable zinc‑air batteries, the engineered catalyst translates its laboratory excellence into practical gains. The cells deliver a peak power density of 190 mW cm⁻² and a specific capacity of 832 mAh g⁻¹, maintaining stable operation over 600 charge‑discharge cycles. These results underscore the commercial relevance of coordinated pore‑structure engineering, suggesting a pathway toward durable, low‑cost metal‑air systems that can support renewable integration and grid storage. Future work will likely explore scaling the wavy graphene platform and extending the methodology to other transition‑metal SACs, broadening the impact across diverse electrochemical technologies.