Electrochemical and Microstructural Evaluation of Aged Nanostructured Thin Film Fuel Cell Electrocatalyst

Kongkanand, Anusorn; Liu, Zhongyi; Dutta, Indrajit; Wagner, Frederick T.

doi:10.1149/1.013111jes

Cited by 22 publications

(15 citation statements)

References 33 publications

(103 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, a recent report has shown that the constituent units of extended thin films composed of polycrystalline 1D nanostructures were found to lose their unique 1D morphology in favor of forming a smooth flat film. 85 By contrast, the TEM results presented in Figure 8 and in our prior reports suggest that the unique 1D morphology of single-crystalline nanostructures presented herein is essentially preserved. Hence, the addition of 10% gold, forming a stabilized uniform alloy, resulted in substantial and quantifiable enhancements with respect to both ORR activity and durability.…”

Section: The Journal Of Physical Chemistry Letterscontrasting

confidence: 71%

“…Comparison of the durability results in the Pt–Pd 9 Au NWs with those obtained from state-of-the-art Pt NP/C catalysts substantiates our assertion that Pt–Pd 9 Au NWs possess superior durability performance. Interestingly, a recent report has shown that the constituent units of extended thin films composed of polycrystalline 1D nanostructures were found to lose their unique 1D morphology in favor of forming a smooth flat film . By contrast, the TEM results presented in Figure and in our prior reports suggest that the unique 1D morphology of single-crystalline nanostructures presented herein is essentially preserved.…”

contrasting

confidence: 39%

See 1 more Smart Citation

Designing Enhanced One-Dimensional Electrocatalysts for the Oxygen Reduction Reaction: Probing Size- and Composition-Dependent Electrocatalytic Behavior in Noble Metal Nanowires

Koenigsmann

Scofield

Liu

et al. 2012

J. Phys. Chem. Lett.

100

View full text Add to dashboard Cite

Despite increasing interest in the use of one-dimensional (1D) noble metal nanostructures for the oxygen reduction reaction, there has been a surprising lack of effort expended in thoroughly and rationally examining the influence of various physicochemical properties of 1D electrocatalysts with respect to their intrinsic performance. In this Perspective, we address this important issue by investigating and summarizing recent theoretical and experimental progress aimed at precisely deducing the nature of the complex interplay among size, chemical composition, and electrocatalytic performance in high-quality elemental and bimetallic 1D noble metal nanowire systems. In terms of these structural parameters, significant enhancements in both activity and durability of up to an order of magnitude in the case of Pt–Pd1–x Au x nanowires, for example, can be achieved by rationally tuning both wire size and composition. The fundamental insights acquired are then utilized to discuss future and potentially radically new directions toward the continuous improvement and optimization of 1D catalysts.

show abstract

Section: The Journal Of Physical Chemistry Letterscontrasting

confidence: 71%

contrasting

confidence: 39%

Designing Enhanced One-Dimensional Electrocatalysts for the Oxygen Reduction Reaction: Probing Size- and Composition-Dependent Electrocatalytic Behavior in Noble Metal Nanowires

Koenigsmann

Scofield

Liu

et al. 2012

J. Phys. Chem. Lett.

100

View full text Add to dashboard Cite

show abstract

“…60 Non electronconducting supports have also been proposed, e.g. the Pt/NSTF from 3M, [64][65][66] but these materials failed to be implemented with success in PEMFC systems on the field, owing to the difficulty to deliver stable electrocatalytic performances in non-perfectly-controlled operation.…”

mentioning

confidence: 99%

Activity and Durability of Platinum-Based Electrocatalysts Supported on Bare or Fluorinated Nanostructured Carbon Substrates

Asset

Chattot

Maillard

et al. 2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

Nanostructured carbons were fluorinated and used as supports for Pt nanoparticles deposition using a modified polyol route. The resulting materials exhibited similar Pt nanoparticles sizes, but different agglomeration rates. The electrocatalysts were tested toward the oxygen reduction reaction, and their stability was investigated in simulated load cycling (0.6 < E < 1.0 V vs. RHE) or start-up/shutdown (1.0 < E < 1.5 V vs. RHE) protocols. Irrespective the support material, the former protocol caused Pt nanocrystallites dissolution/redeposition via Ostwald ripening, mildly decreasing the electrochemically-active surface area and ORR activity. In contrast, the carbon supports were strongly corroded after the start-up/shutdown protocol, resulting in pronounced detachment/agglomeration of Pt nanocrystallites, albeit in absence of significant particle-size growth. Fluorination had different effects on the stability of structurally-ordered and structurally-disordered carbons: beneficial effects were observed for the latter whereas the former was affected negatively. "Free" dangling groups present in structurally-disordered carbon, known to be prone to preferential oxidation in PEMFC environment, combine with the fluorine precursors upon fluorination, leading to formation of more robust C-F bonds versus oxidation than original CO bonds. In contrast, fluorination of structurally-ordered carbon creates structural disorder (C-C bonds are broken), leading to promotion of electrochemical corrosion.

show abstract

“…[7][8][9][10] In addition, owing to its unique structure of an extended surface of Pt covering a support, one expects that the Pt or Pt-alloy layer thickness (and therefore the Pt loading) could be reduced while maintaining the electrochemical properties of the catalyst. 11 Therefore, NSTF catalyst technology provides a plausible pathway for achieving higher ORR activity using small amounts of Pt.…”

mentioning

confidence: 99%

Development of Dispersed-Catalyst/NSTF Hybrid Electrode

Kongkanand¹,

Owejan²,

Moose³

et al. 2012

J. Electrochem. Soc.

View full text Add to dashboard Cite

Ultrathin electrodes, such as the 3M Nanostructured Thin Film (NSTF) electrode, provide a plausible pathway to reduce platinum cost in low temperature fuel cells. However, several operational shortcomings, involving relatively poor electrode proton conduction and tendencies to collect water in the cathode, were observed in our fuel cell tests. This can be greatly mitigated when a few-micron thick dispersed-catalyst layer is placed adjacent to the NSTF layer, forming a dispersed-catalyst/NSTF hybrid electrode. This dispersedcatalyst layer is also called the "interlayer" because it is located between the NSTF layer and the microporous layer of the cathode diffusion medium. In this study, development of the hybrid electrode was pursued. Emphasis on developing lab-scale fabrication methods that can easily translate to roll-to-roll manufacturing process was a key element of the hybrid electrode development. The fuel cell performance of the electrode showed high sensitivity to fabrication methods. When the dispersed-catalyst layer was coated directly on the NSTF electrode, voltage at high current density dropped significantly. The voltage loss was surmised to be caused by ionomer seepage into the NSTF layer during the coating process. This voltage loss could be eliminated by placing the dispersedcatalyst layer on the gas-diffusion layer and then located adjacent to the NSTF cathode. Interaction between the dispersed-catalyst and NSTF layers and how it affects the fuel cell performance is discussed.In a proton exchange membrane fuel cell (PEMFC), Pt or Pt alloy nanoparticles supported on high surface area carbon particles are generally used in the cathode. The highly dispersed nature of the catalyst allows for good utilization of the precious metal. However, the electrochemical stability of the carbon support as well as the dissolution of Pt nanoparticles raise concerns about the durability of the catalyst. 1-4 3M's Nanostructured Thin Film (NSTF) is an extended surface catalyst which consists of a thin film of Pt alloy coated on individual lath-shaped single crystalline whiskers of an organic compound, perylene red (PR149). 5-7 The ∼0.5-1 μm long support whiskers are electrically non-conductive, thereby greatly reducing their susceptibility to electro-oxidative corrosion. The continuous layer of Pt serves as the electrical conductor for the electrode. Due to the low curvature (smaller number of low-coordination-number Pt atoms) and bulk-like characteristics of Pt in this form, NSTF electrodes exhibit higher chemical and electrochemical stability and 5-10 times higher Pt-areaspecific ORR activity than dispersed carbon supported catalysts. 7-10 In addition, owing to its unique structure of an extended surface of Pt covering a support, one expects that the Pt or Pt-alloy layer thickness (and therefore the Pt loading) could be reduced while maintaining the electrochemical properties of the catalyst. 11 Therefore, NSTF catalyst technology provides a plausible pathway for achieving higher ORR activity using small amounts of ...

show abstract

Electrochemical and Microstructural Evaluation of Aged Nanostructured Thin Film Fuel Cell Electrocatalyst

Cited by 22 publications

References 33 publications

Designing Enhanced One-Dimensional Electrocatalysts for the Oxygen Reduction Reaction: Probing Size- and Composition-Dependent Electrocatalytic Behavior in Noble Metal Nanowires

Designing Enhanced One-Dimensional Electrocatalysts for the Oxygen Reduction Reaction: Probing Size- and Composition-Dependent Electrocatalytic Behavior in Noble Metal Nanowires

Activity and Durability of Platinum-Based Electrocatalysts Supported on Bare or Fluorinated Nanostructured Carbon Substrates

Development of Dispersed-Catalyst/NSTF Hybrid Electrode

Contact Info

Product

Resources

About