Enhanced Acidic Water Oxidation by Dynamic Migration of Oxygen Species at the Ir/Nb2O5−x Catalyst/Support Interfaces
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DOI number:
10.1002/anie.202212341
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Journal:
Angew Chem Int Ed Engl
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Abstract:
Catalyst/support interaction plays a vital role
in catalysis towards acidic oxygen evolution (OER), and
the performance reinforcement is currently interpreted
by either strain or electron donation effect. We herein
report that these views are insufficient, where the
dynamic evolution of the interface under potential bias
must be considered. Taking Nb 2 O 5?x supported iridium
(Ir/Nb 2 O 5?x ) as a model catalyst, we uncovered the
dynamic migration of oxygen species between IrO x and
Nb2O5-x during OER. Direct spectroscopic evidence combined with theoretical computation suggests these migrations not only regulate the in situ Ir structure towards boosted activity, but also suppress its overoxidation via spontaneously delivering excessive oxygen from IrOx to Nb2O5-x. The optimized Ir/Nb2O5-x thus
demonstrated exceptional performance in scalable water
electrolyzers, i.e., only need 1.839 V to attain 3 A cm-2
(surpassing the DOE 2025 target), and no activity decay
during a 2000 h test at 2 A cm-2.
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Indexed by:
Journal paper
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Volume:
61
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Page Number:
e202212341
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Translation or Not:
no
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Date of Publication:
2022-10-13
