Oxide-supported Ir nanodendrites with high activity and durability for the oxygen evolution reaction in acid PEM water electrolyzers

Oh, Hyung Suk; Nong, Hong Nhan; Reier, Tobias; Gliech, Manuel; Strasser, Peter

doi:10.1039/c5sc00518c

Cited by 372 publications

(355 citation statements)

References 80 publications

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“…22,23 The CV of the IrO 2 ED-1000 electrode possesses a pair of broad redox peaks, a high current density, and a larger area under the CV compared with those of the other electrodes. Using the CV area as a basis, the degree of the electrochemical performance can be determined.…”

Section: Resultsmentioning

confidence: 99%

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Kim

Cho

Lee

2016

J. Electrochem. Soc.

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The synthesis and electrocatalytic performance of iridium-oxide (IrO 2 ) are reported. IrO 2 was electrochemically deposited on the gold dendrite template prepared by the chronoamperometry. The influence of the synthetic condition on the morphology, phase composition, and accessible surface area of the IrO 2 dendrites was investigated. The optimized IrO 2 dendrites showed an excellent electrocatalytic activity toward oxygen evolution with a low overpotential of 240 mV at 5 mAcm −2 and to the sensing of hydrogen peroxide with a high sensitivity of 692. The advantageous features of iridium oxide (IrO 2 ) include a high stability with exceptional resolution and corrosion resistances, reversible redox properties, and a sound biocompatibility for use in implantable devices. Due to these characteristic features, IrO 2 has been investigated for electrocatalytic applications such as water splitting, [1][2][3] pH sensing, 4,5 and amperometric biosensing; 6,7 however, its high cost and limited abundance require the most-efficient utilization of IrO 2 possible. 8,9 To enhance the electrocatalytic activity of IrO 2 at a low cost, IrO 2 catalyst is designed into a nanostructure. The structurally controlled IrO 2 catalyst can provide a large and accessible active surface area, and it facilitates electro-and mass transport. For these reasons, several researchers have developed the IrO 2 nanostructures in different ways. Electrodeposited IrO 2 nanoparticles for pH sensing were reported by Kim et al. 4 The preparation of IrO 2 nanofibers using electrospinning technique, and their application in ascorbic acid sensor electrode with binder was reported by Kim et al. 6 Sun et al. prepared IrO 2 nanorods using a CdSe/CdS/TiO 2 -nanorod template at 480• C. 10 With the use of a colloidal-SiO 2 template and heat-treatment, macroporous IrO 2 was prepared by Hu et al. 11 The reported IrO 2 structures were prepared via complex processes at high annealing temperatures or with the use of a template that required a multi-step preparation.As is well known, a dendrite structure, consisting of a main stem and numerous side branches, receives significant attention as a catalyst and other technological fields. The large surface area, short diffusion length, and sound mechanical integrity of the dendrite can provide both an extraordinarily high activated surface and a robust stability that are due to the micro-and nano-sized assemblies.12-15 To directly synthesize a metal dendrite on a conductive substrate, electrodeposition can be easily employed without any post-treatment at room temperature.Here, we introduce a simple method to achieve IrO 2 dendrite; the gold dendrite was prepared on titanium (Ti) foil using a facile electrodeposition (ED), and IrO 2 was then electrochemically deposited on the gold dendrite. There are only a few studies on the IrO 2 dendrite in the literature. The dendritic structure of IrO 2 was well controlled by the electrodeposition cycle number. An optimized IrO 2 electrode was applied to the electrocatalytic application f...

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Section: Resultsmentioning

confidence: 99%

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Kim

Cho

Lee

2016

J. Electrochem. Soc.

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“…The Tafel slope for the conventional catalyst at E < 1.43 V was 63 mV, which is close to the 60 mV slope commonly reported for IrO 2 -based electrodes in sulfuric acid solution. 14,18,19,32 The stability test of the IrO x /Nb-SnO 2 catalyst during constant current OER was carried out preliminary in air-saturated 0.1 M HClO 4 solution at 80…”

Section: Electrochemical Characterization Of Iromentioning

confidence: 99%

Remarkable Mass Activities for the Oxygen Evolution Reaction at Iridium Oxide Nanocatalysts Dispersed on Tin Oxides for Polymer Electrolyte Membrane Water Electrolysis

Ohno

Nohara

Kakinuma

et al. 2017

J. Electrochem. Soc.

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In order to reduce the amount of noble metal catalysts for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolysis (PEMWE) while maintaining high efficiency, we synthesized new catalysts: IrO x nanoparticles dispersed on Nb-SnO 2 and Ta-SnO 2 supports with fused-aggregate structures. IrO x nanoparticles with a uniform size of ca. 2 nm were highly dispersed on these supports. The OER activities were evaluated by linear sweep voltammetry (LSV) in 0.1 M HClO 4 at 80 • C using a channel flow electrode cell. The IrO x /Ta-SnO 2 catalysts exhibited an apparent mass activity (MA) of 15 A mg Ir -1 for the OER at 1.5 V vs. RHE, which was 32 times higher than that of a conventional catalyst (mixture of Pt black and IrO 2 powders). This suggests a possible reduction of the loading of the noble metal anode catalyst to a level as low as 0.1 mg cm −2 at a voltage efficiency of 90% at 1 A cm −2 . © The Author Renewable energy sources such as solar and wind powers are sustainable alternatives to fossil fuels, although the electricity generation from such sources is intermittent in nature. Thus, the conversion and storage of surplus renewable electricity to other forms of energy are required for leveling of their large output fluctuations. Water electrolysis makes it possible to produce high purity hydrogen from renewable electric power and thus to level the output fluctuations when combined with stationary fuel cells. Polymer electrolyte membrane water electrolysis (PEMWE) has received much attention because of advantages such as high energy conversion efficiency, even at high current densities, and a compact system with easy maintenance and start-up and shut-down, 1-3 compared to alkaline 4 and solid oxide electrolysis, 5 leading to the feasibility of on-site hydrogen production. Nevertheless, conventional PEMWE cells are very expensive due to their use of a large amount of noble metals such as Pt and/or Ir as electrocatalysts (2 mg Pt+Ir cm −2 or more in each electrode), in addition to their use of costly polymer electrolyte membranes. 3,6 To solve the catalyst problem, one possible approach is to use nano-sized catalysts highly dispersed on support materials in place of noble metal blacks with large particle sizes, typically over 50 nm. For the support material at the anode, high durability at the high potentials of the oxygen evolution reaction (OER) under acidic conditions is required. Carbon supports, which have been commonly used in polymer electrolyte fuel cells (PEFCs), cannot be used due to the severe corrosion at such high potentials. 7,8 Tin oxide, 9 titanium oxide, 10,11 titanium carbide, 12 and silicon carbide-silicon, 13 among others, have been examined as supports for noble metal catalysts for the OER. The OER activities of iridium and/or ruthenium oxide nanoparticle (or nanodendrite) catalysts supported on antimony-doped tin oxide (Sb-SnO 2 ), which exhibited a relatively high electronic conductivity, have been examined by several groups.14-19 However, to our knowledge, the micros...

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“…[7,8] Forwater splitting in PEM electrolyzers,the choice of the oxygen evolution reaction (OER) catalyst employed at the anode has ap rofound impact on the cost, lifetime,a nd efficiency of the device.Iridium is commonly used as aOER catalyst, but is highly priced ($546 per troy ounce) [9] and one of the rarest elements in the earth crust, with an annual production and consumption value of only about 4t o9 tons. [10][11][12] Several approaches have been proposed to overcome the challenges associated with the precious metal OER catalyst such as reducing the particle size,thereby increasing the surface to mass ratio, [13] using electro-ceramic supports, [14,15] or enhancing the phase structure. [16] These characteristics can be modified through different approaches,while adirect modification during synthesis without post-treatment represents an attractive way to reduce production costs influencing the commercialization of future catalysts.…”

Section: Thetotalglobalhydrogenproductionvalueisgreaterthan30mentioning

confidence: 99%

Nanosized IrO_x–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure

et al. 2015

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Abstract:We have developed ah ighly active nanostructured iridium catalyst for anodes of proton exchange membrane (PEM) electrolysis.C lusters of nanosized crystallites are obtained by reducing surfactant-stabilized IrCl 3 in water-free conditions.T he catalyst shows af ive-fold higher activity towards oxygen evolution reaction (OER) than commercial Ir-black. The improved kinetics of the catalyst are reflected in the high performance of the PEM electrolyzer (1 mg Ir cm À2 ), showing an unparalleled low overpotential and negligible degradation. Our results demonstrate that this enhancement cannot be only attributed to increased surface area, but rather to the ligand effect and low coordinate sites resulting in ahigh turnover frequency (TOF). The catalyst developed herein sets ab enchmark and as trategy for the development of ultra-low loading catalyst layers for PEM electrolysis.

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Oxide-supported Ir nanodendrites with high activity and durability for the oxygen evolution reaction in acid PEM water electrolyzers

Abstract: Ir nanodendrites (Ir-ND) supported on antimony doped tin oxide (ATO) show enhanced catalytic activity and stability for oxygen evolution reaction (OER) in polymer electrolyte membrane (PEM) water electrolysis.

Cited by 372 publications

References 80 publications

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Remarkable Mass Activities for the Oxygen Evolution Reaction at Iridium Oxide Nanocatalysts Dispersed on Tin Oxides for Polymer Electrolyte Membrane Water Electrolysis

Nanosized IrO_x–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure

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Oxide-supported Ir nanodendrites with high activity and durability for the oxygen evolution reaction in acid PEM water electrolyzers

Abstract: Ir nanodendrites (Ir-ND) supported on antimony doped tin oxide (ATO) show enhanced catalytic activity and stability for oxygen evolution reaction (OER) in polymer electrolyte membrane (PEM) water electrolysis.

Cited by 372 publications

References 80 publications

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H2O2

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H2O2

Remarkable Mass Activities for the Oxygen Evolution Reaction at Iridium Oxide Nanocatalysts Dispersed on Tin Oxides for Polymer Electrolyte Membrane Water Electrolysis

Nanosized IrOx–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure

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Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Iridium Oxide Dendrite as a Highly Efficient Dual Electro-Catalyst for Water Splitting and Sensing of H₂O₂

Nanosized IrO_x–Ir Catalyst with Relevant Activity for Anodes of Proton Exchange Membrane Electrolysis Produced by a Cost‐Effective Procedure