Dynamic Cr-triggered reconstruction enables Ni-O covalency modulation for industrial-level alkaline oxygen evolution

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for energy conversion but is kinetically hindered.
• Tuning catalyst reconstruction dynamics is a key strategy to boost OER performance.

Purpose of the Study:

• To design a pre-catalyst that guides surface reconstruction towards highly active OER phases.
• To improve the efficiency and durability of the oxygen evolution reaction.

Main Methods:

• Synthesis of a Cr-modified nickel oxalate pre-catalyst on Ni-Mo foam (NMCrH).
• Operando characterization to study surface reconstruction pathways.
• Electrochemical testing to evaluate OER performance.

Main Results:

• NMCrH steers reconstruction to OER-active NiOOH with enhanced Ni-O covalency and lattice oxygen activation.
• The catalyst shifts the OER mechanism from adsorbate evolution (AEM) to the lattice oxygen mechanism (LOM).
• Achieved low overpotential of 248 mV at 10 mA cm^-2 and remarkable durability of 3049 h at 1 A cm^-2.

Conclusions:

• The designed NMCrH catalyst effectively reconciles OER kinetics and stability.
• Optimized surface reconstruction is a viable strategy for advanced electrocatalyst development.
• This work presents a promising catalyst for efficient oxygen evolution.