Electrochemical dealloying in a magnetic field – Tapping the potential for catalyst and material design

Rurainsky, Christian; Nettler, Dean-Robin; Pahl, Thorben; Just, Annika; Cignoni, Paolo; Kanokkanchana, Kannasoot; Tschulik, Kristina

doi:10.1016/j.electacta.2022.140807

Cited by 4 publications

(3 citation statements)

References 41 publications

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“…The Au–O–O–H mode at 813 cm –1 is observed for the first two LSVs but absent from LSV 3 on. This goes along with a change in morphology and catalytic activity, as observed before. , In summary, we conclude that Au-enriched porous nanoparticles are catalytically more active with respect to OER than the corresponding AuNPs, as evidenced spectroscopically by an increased accumulation of Au–O–O–H and shown electrochemically by the shift of OER to lower potentials.…”

Section: Resultssupporting

confidence: 83%

SERS Reveals the Presence of Au–O–O–H and Enhanced Catalytic Activity of Electrochemically Dealloyed AgAu Nanoparticles

et al. 2023

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Due to their high surface-to-volume ratio and large proportion of low coordinated surface atoms, dealloyed nanoparticles have gained increasing attention as porous catalysts for the electrochemical oxygen evolution reaction (OER). Here, we characterize and rationalize the physical and chemical properties of operando gold-enriched porous nanoparticles fabricated by electrochemical dealloying of citrate-capped silver gold alloy nanoparticles in 250 mM KNO3. We combine surface-enhanced Raman spectroscopy (SERS) with electrochemistry for catalyst tracking. With SERS, we observe at 1.05 V (vs platinum quasi-reference electrode) the formation of Au–O–O–H species, a known intermediate of OER, while this is not observed for monometallic gold nanoparticles or bare electrodes. In agreement, qualitative measurements of the catalytic activity prove that appreciable OER currents are detected at lower potentials for gold-enriched porous nanoparticles compared to gold nanoparticles of the same size. Our results pave the way for the application of dealloying-derived nanoparticles as promising catalyst materials.

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Section: Resultssupporting

confidence: 83%

SERS Reveals the Presence of Au–O–O–H and Enhanced Catalytic Activity of Electrochemically Dealloyed AgAu Nanoparticles

et al. 2023

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“…Spin effects in radical reactions are well established. – Magnetic field effects on chemical reactions have been considered by Turro and Kraeutler, Steiner and Ulrich, and Buchachenko . In electrochemistry, magnetic effects are a long established research domain. – Magnetic effects on transport are well developed for uniform and gradient magnetic fields. – ,– Although a magnetic effect on electron transfer might be anticipated based on the coupling of current and electrical and magnetic fields and gradients in electromagnetic theory, magnetic effects on electron transfer are not well resolved. Careful studies in uniform magnetic fields have identified no impacts on electron transfer for electrode materials with or without unpaired electrons. , Here, magnetic gradients are identified as a critical component in the magnetoelectrocatalysis of HER.…”

Section: Discussionmentioning

confidence: 99%

“…Magnetic fields and gradients impact mass transport through interaction with the charge and spin of chemical species. Magnetohydrodynamics (MHD) describes interaction of magnetic fields with ion flux in solution to generate a Lorentz force that alters bulk fluid flow. – Gradient magnetic fields are shown to interact with spin and charge to disrupt and enhance mass transport in fluids. ,– Magnetically driven mass transport occurs in bulk solvent …”

Section: Discussionmentioning

confidence: 99%

Magnetoelectrocatalysis: Evidence from the Hydrogen Evolution Reaction

Knoche Gupta,

Lee,

Leddy

2024

ACS Phys. Chem Au

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Hydrogen evolution reaction (HER) rates are higher where magnetic gradients are established at electrode surfaces. In comparison of literature data for metals with comparable work functions, we note 1000× higher rates for paramagnetic metals than diamagnetic metals. With unpaired electron spins, paramagnetic and ferromagnetic metals establish interfacial magnetic gradients. At diamagnetic electrodes, gradients are induced by addition of magnetized microparticles. Onset of hydrogen evolution for magnetized γ-Fe 2 O 3 microparticles in Nafion on diamagnetic glassy carbon electrodes is lower by 190 mV (−18 kJ mol −1 ) relative to demagnetized microparticles. Chemically the same as demagnetized particles, the physical distinction of magnetic field and gradient at magnetized microparticles increases electron transfer rate. For magnetized Fe 3 O 4 microparticles, the onset is lower by 280 mV (−27 kJ mol −1 ). Paramagnetic platinum electrodes are unaffected by addition of magnetized microparticles. Magnetoelectrocatalysis is established by magnetic gradients.

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Why standard electrokinetic analysis often fails for nanostructured electrodes - Reviewing inhomogeneous electroactivity

Cignoni

Blanc

Tschulik

2023

Current Opinion in Electrochemistry

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Electrochemical dealloying in a magnetic field – Tapping the potential for catalyst and material design

Cited by 4 publications

References 41 publications

SERS Reveals the Presence of Au–O–O–H and Enhanced Catalytic Activity of Electrochemically Dealloyed AgAu Nanoparticles

SERS Reveals the Presence of Au–O–O–H and Enhanced Catalytic Activity of Electrochemically Dealloyed AgAu Nanoparticles

Magnetoelectrocatalysis: Evidence from the Hydrogen Evolution Reaction

Why standard electrokinetic analysis often fails for nanostructured electrodes - Reviewing inhomogeneous electroactivity

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