Reviving Oxygen Evolution Electrocatalysis of Bulk La-Ni Intermetallics via Gaseous Hydrogen Engineering.
Ziliang ChenHongyuan YangStefan MebsHolger DauMatthias DriessZhaowu WangZhenhui KangPrashanth Wilfred MenezesPublished in: Advanced materials (Deerfield Beach, Fla.) (2023)
A hydrogen processing strategy is developed to enable bulk LaNi 5 to attain high activity and long-term stability toward the electrocatalytic oxygen evolution reaction (OER). By a combination of in situ Raman and quasi in situ X-ray absorption (XAS) spectra, secondary-electron-excited scanning transmission electron microscopy (STEM) patterns as well as the Rietveld method and density functional theory (DFT) calculations, it is discovered that hydrogen-induced lattice distortion, grain refinement, and particle cracks dictate the effective reconstruction of the LaNi 5 surface into a porous hetero-nanoarchitecture composed of uniformly confined active γ-NiOOH nanocrystals by La(OH) 3 layer in the alkaline OER process. This significantly optimizes the charge transfer, structural integrity, active-site exposure, and adsorption energy toward the reaction intermediates. Benefiting from these merits, the overpotential (322 mV) at 100 mA cm -2 for the hydrogen-processed OER catalyst deposited on nickel foam is reduced by 104 mV as compared to the original phase. Notably, it exhibits remarkable stability for 10 days at an industrial-grade current density of more than 560 mA cm -2 in alkaline media.
Keyphrases
- density functional theory
- electron microscopy
- molecular dynamics
- metal organic framework
- visible light
- reduced graphene oxide
- high resolution
- room temperature
- electron transfer
- gold nanoparticles
- high glucose
- heavy metals
- magnetic resonance
- computed tomography
- molecular dynamics simulations
- risk assessment
- endothelial cells
- energy transfer
- crystal structure
- raman spectroscopy