Heat‐Triggered Ferri‐to‐Paramagnetic Transition Accelerates Redox Couple‐Mediated Electrocatalytic Water Oxidation

Redox couple oxidation as an initial step of water oxidation may be key for high electricity consumption in the electrochemical oxygen evolution reaction (OER). Here, a heat‐induced magnetic transition strategy is reported to speed up the oxidation kinetics of redox couples. The activation energy of...

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Bibliographic Details
Published in:Advanced functional materials 2022-08, Vol.32 (32), p.n/a
Main Authors: Liu, Duanduan, Lu, Mengfei, Liu, Depei, Yan, Shicheng, Zhou, Wei, Zhang, Lunyong, Zou, Zhigang
Format: Article
Language:English
Subjects:
Catalysts
Curie temperature
Electricity consumption
Electrolytes
heat–electricity coupling
magnetic phase transition
Magnetic transitions
Materials science
multienergy complementary
Oxidation
Oxygen evolution reactions
Reaction kinetics
redox couples
water oxidation
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Summary:Redox couple oxidation as an initial step of water oxidation may be key for high electricity consumption in the electrochemical oxygen evolution reaction (OER). Here, a heat‐induced magnetic transition strategy is reported to speed up the oxidation kinetics of redox couples. The activation energy of Ni2+/Ni3+ redox couple oxidation is sharply decreased by heating the Ni0.67Fe0.33OxHy catalyst above a Curie temperature (Tc) of 70 °C. In such a strategy, heat instead of electricity drives the spin flipping of Ni2+/Ni3+ oxidation through heat‐sensitive ferri‐to‐paramagnetic spin state changes. As a result of magnetic transition‐assisted efficient heat‐electricity coupling, Ni0.67Fe0.33OxHy exhibits the lowest OER overpotential of 221 mV at 100 mA cm−2 at 90 °C in alkaline electrolytes, outperforming the benchmark IrO2 catalyst. The findings provide new insights into the design of efficient heat–electricity complementary OER devices. A heat‐induced magnetic transition strategy is proposed to accelerate the oxidation kinetics of catalytic redox couple, a vital initial oxygen evolution reaction step, aiming to achieve ferri‐to‐paramagnetic spin flipping by heat instead of electricity. This strategy provides a solid physical basis for heat‐electricity coupling and unlocks the great potential of heat–electricity complementary water electrolysis by utilizing a low‐grade thermal field.
ISSN:1616-301X
1616-3028
DOI:10.1002/adfm.202111234