Oxygen Reduction Activity of PtxNi1-x Alloy Nanoparticles on Multiwall Carbon Nanotubes

Kim, Junhyung; Lee, Seung Woo; Carlton, Christopher E.; Shao‐Horn, Yang

doi:10.1149/1.3613677

Cited by 29 publications

(38 citation statements)

References 34 publications

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“…correction for catalysts evaluated in this work as well as that reported in literature. 4,26,74,82,83 The b.g. correction trends observed in the literature qualitatively agree with the behavior discussed above.…”

Section: Resultsmentioning

confidence: 99%

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Shinozaki

Zack

Richards

et al. 2015

J. Electrochem. Soc.

308

351

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The rotating disk electrode (RDE) technique is being extensively used as a screening tool to estimate the activity of novel PEMFC electrocatalysts synthesized in lab-scale (mg) quantities. Discrepancies in measured activity attributable to glassware and electrolyte impurity levels, as well as conditioning, protocols and corrections are prevalent in the literature. The electrochemical response to a broad spectrum of commercially sourced perchloric acid and the effect of acid molarity on impurity levels and solution resistance were also assessed. Our findings reveal that an area specific activity (SA) exceeding 2.0 mA/cm 2 (20 mV/s, 25 • C, 100 kPa, 0.1 M HClO 4 ) for polished poly-Pt is an indicator of impurity levels that do not impede the accurate measurement of the ORR activity of Pt based catalysts. After exploring various conditioning protocols to approach maximum utilization of the electrochemical area (ECA) and peak ORR activity without introducing catalyst degradation, an investigation of measurement protocols for ECA and ORR activity was conducted. Down-selected protocols were based on the criteria of reproducibility, duration of experiments, impurity effects and magnitude of pseudo-capacitive background correction. Statistical reproducibility of ORR activity for poly-Pt and Pt supported on high surface area carbon was demonstrated.

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Section: Resultsmentioning

confidence: 99%

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Shinozaki

Zack

Richards

et al. 2015

J. Electrochem. Soc.

308

351

View full text Add to dashboard Cite

show abstract

“…Once the catalyst surface was fully activated, CVs were recorded at scan rates of 100 mV/s and then 10 mV/s. Pt electrochemically active surface area (ESA) was calculated from the charge associated with the hydrogen under-potential deposition on Pt (210 μc/cm 2 ) [2,5] after double layer current subtraction. The ORR activity was measured by anodic linear sweep voltammetry (LSV) in an O 2 saturated electrolyte between potentials 0.08 V and 1.1 V at a scan rate of 10 mV/s and rotation speeds ranging from 200 rpm to 1600 rpm.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

“…Despite the significant advances over the past decades, ORR catalyst activity [2] and stability [3][4][5] remain key challenges for widespread commercialization. High ORR activity is typically obtained through the use of highly dispersed platinum crystallites on conductive high surface area supports.…”

Section: Introductionmentioning

confidence: 99%

“…Overpotentials for the ORR [5], however, limit the efficiency of the PEMFC and contribute to a high system cost. Research addressing the low activity of Pt electrocatalysts has focused on developing Pt alloys primarily with transition metals [5], with special attention to Co [6,7] and Ni [2,8] Pt alloys. Stability studies on Pt-alloys have led to the theory that the outer layer of the Pt alloy nanoparticles undergoes segregation and dealloying steps where the particles develop a highly active Pt monolayer on top of the alloy core.…”

Section: Introductionmentioning

confidence: 99%

“…Stability studies on Pt-alloys have led to the theory that the outer layer of the Pt alloy nanoparticles undergoes segregation and dealloying steps where the particles develop a highly active Pt monolayer on top of the alloy core. This has been shown to weaken the bond strength of the oxygen-oxygen bond relative to pure Pt [2,6]. This observation has led to the innovative development of highly active and stable core-shell electrocatalysts [8,9].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Pt and Pt/Ni "Needle" Eletrocatalysts on Carbon Nanotubes with High Activity for the ORR

Elvington

Colón-Mercado

2011

Electrochemical and Solid-State Letters

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Oxygen Reduction Reaction Performance of [MTBD][beti]‐Encapsulated Nanoporous NiPt Alloy Nanoparticles

Snyder¹,

Livi²,

Erlebacher³

2013

Adv Funct Materials

176

215

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Recent advances in oxygen reduction reaction catalysis for proton exchange membrane fuel cells (PEMFCs) include i) the use of electrochemical dealloying to produce high surface area and sometimes nanoporous catalysts with a Pt‐enriched outer surface, and ii) the observation that oxygen reduction in nanoporous materials can be potentially enhanced by confinement effects, particularly if the chemical environment within the pores can bias the reaction toward completion. Here, these advances are combined by incorporating a hydrophobic, protic ionic liquid, [MTBD][beti], into the pores of high surface‐area NiPt alloy nanoporous nanoparticles (np‐NiPt/C + [MTBD][beti]). The high O2 solubility of the [MTBD][beti], in conjunction with the confined environment within the pores, biases reactant O2 toward the catalytic surface, consistent with an increased residence time and enhanced attempt frequencies, resulting in improved reaction kinetics. Half‐cell measurements show the np‐NiPt/C+[MTBD][beti] encapsulated catalyst to be nearly an order of magnitude more active than commercial Pt/C, a result that is directly translated into operational PEMFCs.

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Oxygen Reduction Activity of PtxNi1-x Alloy Nanoparticles on Multiwall Carbon Nanotubes

Cited by 29 publications

References 34 publications

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Pt and Pt/Ni "Needle" Eletrocatalysts on Carbon Nanotubes with High Activity for the ORR

Oxygen Reduction Reaction Performance of [MTBD][beti]‐Encapsulated Nanoporous NiPt Alloy Nanoparticles

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