Iridium nanoparticles for the oxygen evolution reaction: Correlation of structure and activity of benchmark catalyst systems

Rakousky, Christoph; Shviro, Meital; Stolten, Detlef

doi:10.1016/j.electacta.2018.11.141

Cited by 27 publications

(29 citation statements)

References 29 publications

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“…It can be seen that IrO2-AA shows higher activity that rutile IrO2 as shown in Figure S5, agreeing with recent reports. [30][31][32][33] However, the normalized activity of Li-IrOx is still higher compared with IrO2-AA and IrO2-AA-400. The Tafel slope for rutile IrO2 is 68 mV dec -1 while that for Li-IrOx is only 39 mV dec -1 , further proving the advantage of Li-IrOx in OER (Figure 3b).…”

Section: Resultsmentioning

confidence: 97%

“…Figure S3 displays the specific activity normalized to surface area, Ir mass, and ECSA as well as turn over frequency (TOF), confirming the superiority of amorphous Li–IrO x . Moreover, another commercial iridium oxide (IrO 2 -AA) with high surface area of 35 m 2 /g, which contains significant amount of amorphous phase, and the annealed one (IrO 2 -AA-400) were also compared (Figure S4). It can be seen that IrO 2 -AA shows higher activity than rutile IrO 2 as shown in Figure S5, agreeing with recent reports. − However, the normalized activity of Li–IrO x is still higher compared with IrO 2 -AA and IrO 2 -AA-400.…”

Section: Resultsmentioning

confidence: 99%

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Breaking Long-Range Order in Iridium Oxide by Alkali Ion for Efficient Water Oxidation

et al. 2019

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Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Breaking Long-Range Order in Iridium Oxide by Alkali Ion for Efficient Water Oxidation

et al. 2019

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“…In this study, we use Ir black nanoparticles, which are typically used as benchmark for Ir based catalyst for OER in acidic media. [16,49,50] The Ir nanoparticles present a size of ca. 4-5 nm.…”

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confidence: 99%

Electrolyte Effects on the Electrocatalytic Performance of Iridium‐Based Nanoparticles for Oxygen Evolution in Rotating Disc Electrodes

Arminio‐Ravelo

Jensen

et al. 2019

ChemPhysChem

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Proton exchange membrane water electrolysers are very promising renewable energy conversion devices that produce hydrogen from sustainable feedstocks. These devices are mainly limited by the sluggish kinetics of the oxygen evolution reaction (OER). Ir‐based nanoparticles are both reasonably active and stable for the OER in acidic media. The electrolyte composition and the pH may play a crucial role in electrocatalysis, yet they have been widely overlooked for the OER. Herein, we present a study on the effects of the composition and concentration of the electrolyte on commercial Ir black nanoparticles using concentrations of 0.05 M, 0.1 M and 0.5 M of both sulphuric and perchloric acid. The results show an important effect of the electrolyte composition on the catalytic performance of the Ir nanoparticles. The concentration of H2SO4 interferes on the oxidation of Ir and decreases the catalytic performance of the catalyst. HClO4 does not show strong interferences in the electrochemistry of Ir. Higher catalytic performances are observed in HClO4 electrolytes in comparison to H2SO4 with little effect of the concentration of HClO4.

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“…This competition underscores the complex interplay between CER and OER. As such, we seek to understand this interplay electroanalytically by evaluating a series of iridium (Ir)‐based electrocatalysts, as Ir is one of the most electroactive catalysts for OER in acidic electrolytes . The high cost of Ir has resulted in efforts focused on reducing the overall loading of the required precious metals, while still supporting high electrocatalytic activity .…”

Section: Figurementioning

confidence: 99%

“…As such, we seek to understand this interplay electroanalytically by evaluating a series of iridium (Ir)-based electrocatalysts, as Ir is one of the most electroactive catalysts for OER in acidic electrolytes. [24,25,26] The high cost of Ir has resulted in efforts focused on reducing the overall loading of the required precious metals, while still supporting high electrocatalytic activity. [27,28] Based on the high performance and chemical stability of Ir-based electrocatalysts for OER in acidic electrolytes, and given the literature reports of improving electrocatalytic activity of non-precious metal catalysts on carbon supports, [29,30,31,32] we chose to study the activity of pyrolyzed Irbased organometallics embedded within a high surface area carbonaceous support.…”

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confidence: 99%

Decoupling Oxygen and Chlorine Evolution Reactions in Seawater using Iridium‐based Electrocatalysts

Johnson

et al. 2020

ChemCatChem

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A series of iridium (Ir) organometallic-based electrocatalysts fused onto high surface-area activated carbon using pyrolysis were prepared for the oxygen evolution reaction (OER) in seawater electrolysis. These catalysts had a low loading of Ir (< 6 wt%), while also inducing atom coordination to the Ir center. The morphology and chemical composition of these electrocatalysts were analyzed by scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy, which all showed a uniform dispersion of Ir and heteroatom-doped moieties. To assess electrocatalytic activity, we used an artificial electrolyte comprising 0.1 M HClO 4 + 3.5 wt % NaCl, and found that these catalysts delivered a low overpotential of 243 mV, a low Tafel slope (92 mV dec À 1), and a high exchange current density (1.4 mA cm À 2). By using a headspace chlorine gas (Cl 2) detector in situ, we discovered that a Cl 2 content of 27 ppm was present. When tested in synthetic seawater, the overpotential exhibited a twofold increase, yet Cl 2 was undetected, thus indicating favorable OER kinetics. This significant finding exemplifies the need for in situ Cl 2 detection for seawater splitting research, since further insight can be derived to help guide the design of novel electrocatalysts.

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Iridium nanoparticles for the oxygen evolution reaction: Correlation of structure and activity of benchmark catalyst systems

Cited by 27 publications

References 29 publications

Breaking Long-Range Order in Iridium Oxide by Alkali Ion for Efficient Water Oxidation

Breaking Long-Range Order in Iridium Oxide by Alkali Ion for Efficient Water Oxidation

Electrolyte Effects on the Electrocatalytic Performance of Iridium‐Based Nanoparticles for Oxygen Evolution in Rotating Disc Electrodes

Decoupling Oxygen and Chlorine Evolution Reactions in Seawater using Iridium‐based Electrocatalysts

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