Kinetics and Mechanism of Oxidation of L-Ascorbic Acid by Pt(IV)(aq) in Aqueous Hydrochloric Acid Medium

Senapati, Sadhana; Das, Smruti Prava; Patnaik, Ajaya Kumar

doi:10.1155/2012/143734

Cited by 10 publications

(4 citation statements)

References 20 publications

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“…Therefore, the Pt(IV) ion was chosen in this study to obtain a slow reduction speed. Ascorbic acid was used as a weak reductant to reduce Pt(IV) ion 70 . In this process, the spiny Au NPs provided a nucleation center, and the Pt atoms were uniformly and slowly reduced on the surface of the spiny Au NPs.…”

Section: Resultsmentioning

confidence: 99%

A self-supporting bimetallic Au@Pt core-shell nanoparticle electrocatalyst for the synergistic enhancement of methanol oxidation

Tan

Sun

Zheng

et al. 2017

Sci Rep

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The morphology of Pt−Au bimetal nanostructures plays an important role in enhancing the catalytic capability, catalytic stability and utilization efficiency of the platinum. We designed and successfully prepared Au@Pt nanoparticles (NPs) through an economical, surfactant-free and efficient method of seed-mediated growth. The Au@Pt NPs displayed electrochemical performances superior to those of commercial Pt/C catalysts because their agglomeration was prevented and exhibited better long-term stability with respect to methanol oxidation in acidic media by efficiently removing intermediates. Among the obtained Au@Pt NPs, Au90@Pt10 NPs exhibited the most significantly enhanced catalytic performance for the methanol oxidation reaction (MOR). Their mass and electrochemically active surface area (ECSA)-normalized current densities are approximately 3.9 and 4.6 times higher than those of commercial Pt/C catalysts, respectively. The oxidation current densities of the Au90@Pt10 NPs are approximately 1.8 times higher than those of commercial Pt/C catalysts after 4000 s of continuous measurement because the small Pt NPs grown on the surface of the Au90@Pt10 NPs were effectively stabilized by the Au metal support. This approach may be a facile method for the synthesis of self-supported bimetallic nanostructures, which is of great significance for the development of high performance electrocatalysts and sensors.

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Section: Resultsmentioning

confidence: 99%

A self-supporting bimetallic Au@Pt core-shell nanoparticle electrocatalyst for the synergistic enhancement of methanol oxidation

Tan

Sun

Zheng

et al. 2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The synthesis procedure is adopted from prior literature reports, where Pt(IV) salts have been shown to undergo reduction to metallic Pt with two equivalents of ascorbic acid. [44][45][46][47][48][49] Sodium polyacrylate polymer as a capping agent offers narrow particle size distribution and has been reported previously for Pt synthesis. [50][51][52][53][54][55][56] Alkalizing the reaction mixture with sodium hydroxide destabilizes the colloid and facilitates removal of the polyacrylate from the nanoparticle.…”

Section: Catalyst Synthesis and Decappingmentioning

confidence: 92%

Unsupported Pt nanoparticles: Synthesis, Deactivation, and Hydrogen Electrocatalysis in Unpurified Electrolytes

Patil

Meng

McKone

2021

Preprint

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We synthesized clean unsupported Pt nanoparticles (NPs) which can be used for any electrochemical measurements without the need for additional cleaning steps. In this report, we demonstrated the use of these unsupported Pt NPs for electrochemical reactions involving hydrogen. We further identified conditions under which Pt NPs deactivate in unpurified, reagent grade acid, and alkaline electrolytes, and differentiated between degradation mechanisms involving catalyst poisoning and particle growth. We monitored the degradation of Pt NPs as a function of a decrease in the electrochemically active surface area (ECSA) at different applied potentials. The results obtained from the ECSA measurements were then correlated with the identical location transmission electron microscopy (IL-TEM) observations. At potentials less than 1 V vs RHE, catalyst poisoning was found to be a dominant cause for degradation while particle growth was dominant at 1.5 V vs RHE in both acid and alkaline electrolytes.

show abstract

“…The synthesis procedure is adopted from prior literature reports, where Pt (IV) salts have been shown to undergo reduction to metallic Pt with two equivalents of ascorbic acid. [44][45][46][47][48][49] Sodium polyacrylate polymer as a capping agent offers narrow particle size distribution and has been reported previously for Pt synthesis. [50][51][52][53][54][55] Alkalizing the reaction mixture with sodium hydroxide destabilizes the colloid and facilitates removal of the polyacrylate from the NPs.…”

Section: Resultsmentioning

confidence: 92%

Unsupported Pt Nanoparticles: Synthesis, Deactivation, and Hydrogen Electrocatalysis in Unpurified Electrolytes

Patil,

Roenigk,

Shirwalkar

et al. 2024

J. Electrochem. Soc.

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Platinum is ubiquitous in electrochemical catalysis owing to its ability to accelerate redox reactions involving surface-bound hydrogen and oxygen. Accordingly, Pt is used as a calibration standard and activity benchmark against which novel electrocatalysts are compared. These measurements are often executed in unpurified, reagent grade electrolytes where Pt is also susceptible to deactivation by several routes. This constitutes a challenge where the ease of making measurements with Pt-based catalysts must be balanced against the difficulty of obtaining accurate and consistent results. We report herein a synthetic procedure for unsupported Pt nanoparticles that uses readily available reagents and laboratory apparatus, with the goal of making high-quality control experiments in electrocatalysis as accessible as possible. We also identified conditions under which these particles deactivate in unpurified aqueous acid and base and differentiated between mechanisms involving catalyst poisoning, which dominates at more negative applied potentials, and particle growth, which dominates at positive potentials where Pt-oxide species are produced. Finally, we demonstrated that unsupported Pt nanoparticle films can be used to good effect for reference electrode calibration and benchmarking of hydrogen evolution/oxidation electrocatalysts, even in unpurified electrolytes, provided steps are taken to minimize the impact of deactivation.

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Kinetics and Mechanism of Oxidation of L-Ascorbic Acid by Pt(IV)(aq) in Aqueous Hydrochloric Acid Medium

Cited by 10 publications

References 20 publications

A self-supporting bimetallic Au@Pt core-shell nanoparticle electrocatalyst for the synergistic enhancement of methanol oxidation

A self-supporting bimetallic Au@Pt core-shell nanoparticle electrocatalyst for the synergistic enhancement of methanol oxidation

Unsupported Pt nanoparticles: Synthesis, Deactivation, and Hydrogen Electrocatalysis in Unpurified Electrolytes

Unsupported Pt Nanoparticles: Synthesis, Deactivation, and Hydrogen Electrocatalysis in Unpurified Electrolytes

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