Lattice oxygen activation enabled by high-valence metal sites for enhanced water oxidation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32792524.
- Also identified by DOI 10.1038/s41467-020-17934-7 and PMC identifier 7426847.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Anodic oxygen evolution reaction (OER) is recognized as kinetic bottleneck in water electrolysis. Transition metal sites with high valence states can accelerate the reaction kinetics to offer highly intrinsic activity, but suffer from thermodynamic formation barrier. Here, we show subtle engineering of highly oxidized Ni<sup>4+</sup> species in surface reconstructed (oxy)hydroxides on multicomponent FeCoCrNi alloy film through interatomically electronic interplay. Our spectroscopic investigations with theoretical studies uncover that Fe component enables the formation of Ni<sup>4+</sup> species, which is energetically favored by the multistep evolution of Ni<sup>2+</sup>→Ni<sup>3+</sup>→Ni<sup>4+</sup>. The dynamically constructed Ni<sup>4+</sup> species drives holes into oxygen ligands to facilitate intramolecular oxygen coupling, triggering lattice oxygen activation to form Fe-Ni dual-sites as ultimate catalytic center with highly intrinsic activity. As a result, the surface reconstructed FeCoCrNi OER catalyst delivers outstanding mass activity and turnover frequency of 3601 A g<sub>metal</sub><sup>-1</sup> and 0.483 s<sup>-1</sup> at an overpotential of 300 mV in alkaline electrolyte, respectively.