Engineering Lattice Oxygen Activation of Iridium Clusters Stabilized on Amorphous Bimetal Borides Array for Oxygen Evolution Reaction

• Developing robust oxygen evolution reaction (OER) catalysts requires significant advances in material design and in-depth understanding for water electrolysis. Herein, we report iridium clusters stabilized surface reconstructed oxyhydroxides on amorphous metal borides array, achieving an ultralow overpotential of 178 mV at 10 mA cm−2 for OER in alkaline medium. The coupling of iridium clusters induced the formation of high valence cobalt species and Ir–O–Co bridge between iridium and oxyhydroxides at the atomic scale, engineering lattice oxygen activation and non-concerted proton-electron transfer to trigger multiple active sites for intrinsic pH-dependent OER activity. The lattice oxygen oxidation mechanism (LOM) was confirmed by in situ 18O isotope labeling mass spectrometry and chemical recognition of negative peroxo-like species. Theoretical simulations reveal that the OER performance on this catalyst is intrinsically dominated by LOM pathway, facilitating the reaction kinetics. This work not only paves an avenue for the rational design of electrocatalysts, but also serves the fundamental insights into the lattice oxygen participation for promising OER application.

Ämnesord

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

Nyckelord

electrocatalytic water splitting

iridium clusters

lattice oxygen oxidation mechanism

metal borides

oxygen evolution reaction

Alkalinity

Chemical activation

Cobalt compounds

Iridium compounds

Mass spectrometry

Oxygen

Reaction kinetics

Electrocatalytic

Lattice oxygen

Metal boride

Oxidation mechanisms

Oxygen activations

Water splitting

]+ catalyst

Electrocatalysts

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