Spatiotemporal Control of MOF Reconstruction Unlocks Efficient Oxygen Evolution

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Understanding the dynamic reconstruction of metal-organic frameworks (MOFs) during oxygen evolution reactions (OER) is crucial for developing efficient and durable OER catalysts.
• Current knowledge of these reconstruction mechanisms remains limited.

Purpose of the Study:

• To pioneer a spatiotemporally decoupled reconstruction strategy for dual-metal-node MOF catalysts.
• To elucidate the atomic-to-mesoscale reconstruction kinetics and mechanisms governing OER in MOFs.
• To establish a methodology for tracking structural dynamics and understanding structure-activity relationships under operando conditions.

Main Methods:

• Engineered a dual-metal-node MOF catalyst ([Fe3O(hbdc)3][Ni2(trz)3]) with a purpose-partitioned pore architecture.
• Developed a multimodal operando diagnostic platform integrating in situ X-ray absorption spectroscopy (XAS) and in situ Raman spectroscopy.
• Utilized real-time reaction kinetics tracing to decipher reconstruction processes.

Main Results:

• Demonstrated that orbitally coupled pore-microenvironments drive time-phased kinetic reconstruction of Fe/Ni metal nodes.
• Deciphered the MOF reconstruction from Fe-centered to a more active NiFe-centered phase.
• Observed synergistic interplay between Fe-Ni nodes, self-adaptive defects, bond relaxation, and structural regeneration, leading to enhanced OER activity.

Conclusions:

• Established a foundational platform to reveal MOF reconstruction mechanisms and cross-scale kinetics during OER.
• The developed methodology integrates multi-scale characterization for deep insights into MOF dynamics.
• This work fills a critical gap in understanding MOF structure-activity relationships under operando conditions for OER catalysis.