Micro Galvanic Cell To Generate PtO and Extend the Triple-Phase Boundary during Self-Assembly of Pt/C and Nafion for Catalyst Layers of PEMFC

Long, Zhi; Gao, Liqin; Li, Yankai; Kang, Baotao; Lee, Jin Yong; Ge, Junjie; Liu, Changpeng; Ma, Shengqian; Zhao, Jianmin; Ai, Hongqi

doi:10.1021/acsami.7b11852

Cited by 14 publications

(8 citation statements)

References 17 publications

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“…To make the technology economically viable, a reduction in the Pt loading 5 and an increase in the efficient Pt surface area should be established simultaneously to obtain an excellent PEMFC activity and stability [6][7][8] . In addition, an improvement in the fuel cell efficiency has been associated with the optimized three-phase interface that is composed of an ion-conducting electrolyte (ionomer) next to a solid catalyst surface [9][10][11][12] . After reacting H 2 gas molecules in the solid phase of the anode, the protons meet in the electrolyte phase and then react with O 2 in the solid-electrolyte interface, producing water as a byproduct 13 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of highly dispersed Pt nanoparticles into carbon supports by fluidized bed reactor atomic layer deposition to boost PEMFC performance

et al. 2020

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The performance of proton exchange membrane fuel cells (PEMFCs) depends on the controlled size, dispersion and density of Pt nanoparticles (NPs) on carbon supports, which are strongly affected by the carbon characteristics and fabrication methods. Here, we demonstrated a high-performance Pt/carbon catalyst for PEMFCs using fluidized bed reactor atomic layer deposition (FBR-ALD) that was realized by an effective matching of the carbon supports for the FBR-ALD process and an optimization of the ionomer content during the preparation of the membrane electrode assembly (MEA). For this, the synthesis of Pt NPs was conducted on two porous supports (Vulcan XC-72R and functionalized carbon) by FBR-ALD. The functionalized carbon possessed a higher surface area with a large pore volume, abundant defects in a disordered structure and a large number of oxygen functional groups compared to those of the well-known Vulcan carbon. The favorable surface characteristics of the functionalized carbon for nucleation produced Pt particles with an increased uniformity and density and a narrow size range, which led to a higher electrochemical surface area (ECSA) than that of Pt/Vulcan carbon and commercial Pt/carbon. The PEMFC test of the respective Pt/carbon samples was investigated, and highly dense and uniform Pt/functionalized-carbon showed the highest performance through optimization of the higher ionomer content compared to that for the ALD Pt growth on Vulcan carbon and commercial Pt/carbon. In addition, the Pt catalyst using ALD demonstrated a significant long-term stability for the PEMFC. This finding demonstrates the remarkable advantages of FBR-ALD for the fabrication of Pt/carbon and the ability of functionalized carbon supports to achieve a high PEMFC efficiency and an enhanced durability.

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Section: Introductionmentioning

confidence: 99%

Synthesis of highly dispersed Pt nanoparticles into carbon supports by fluidized bed reactor atomic layer deposition to boost PEMFC performance

et al. 2020

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“…However, when the reaction temperature further increase to 60°C, the appearance of PtO or PtOH on the surface of Pt leads to a turnover of Nafion structure. As a result, more hydrophilic sulfonic groups directly contact with Pt which will be benefit for more TPIs established [41][42][43][44][45]. Meanwhile, it is clear to observe that the high and over region showed a similar ORR trend as low region.…”

Section: Orr Performance By Linear Scanning Voltammetrymentioning

confidence: 91%

Electrochemical study of temperature and Nafion effects on interface property for oxygen reduction reaction

Chen

Zhong²,

et al. 2018

Ionics

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With the growth of new energy economy, proton exchange membrane fuel cell (PEMFC) has great potential to be success. However, the lack of high-performance catalyst layer (CL) especially at cathode limits its applications. It is becoming increasingly important to understand interface property during electrocatalytic oxygen reduction reaction (ORR). Here, the rotating disk electrode (RDE) method is developed to study the temperature and Nafion ionomer content effects on interface formed between Nafion and Pt/C. The results show that the temperature has the significant influence on electrochemical active sites, charging double capacitance, and reaction polarization resistance at low Nafion content region. Excess Nafion loaded in CLs will turn to self-reunion and increase the exposed active sites. We find that the optimum Nafion loading is in the range of 30 to 40 wt.%. The highest specific activity we achieve is 107.8 μA/cm 2 .Pt at 60°C with 0.4 of ionomer/catalyst weight ratio, corresponding to the kinetic current 283.5 μA at 0.9 V. This finding provides new insights into enhancing the Pt utilization and designing high-efficiency catalysts for ORR.

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“…2, the interface (red hollow circle)among the catalyst for conducting electrons, electrolyte phase for conducting protons and pores for transporting gases and/ or water is named as TPB. This concept has been generally used in the study of electrode structure to explain the complex interaction within the CL [20,21].…”

Section: Triple-phase Boundary (Tpb)mentioning

confidence: 99%

“…Typically, the catalyst layer is a thin film composed of carbon-supported highly dispersed Pt catalyst nanoparticles and Nafion ionomer additive [22]. The microstructure and composition of the CL have a great influence on its power performance [20,[23][24][25][26]. Therefore, many research efforts have been made to optimize the TPB properties within the CL, which can be divided into three strategies: (i) adopting highly active catalysts to promote the intrinsic ORR activity, (ii) introducing novel ionomers to enhance conductivity and (iii) improving catalyst/ionomer interface to extend TPB zones [27,28].…”

Section: Triple-phase Boundary (Tpb)mentioning

confidence: 99%

Cathode Design for Proton Exchange Membrane Fuel Cells in Automotive Applications

Wang

Sui

et al. 2021

Automot. Innov.

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An advanced cathode design can improve the power performance and durability of proton exchange membrane fuel cells (PEMFCs), thus reducing the stack cost of fuel cell vehicles (FCVs). Recent studies on highly active Pt alloy catalysts, short-side-chain polyfluorinated sulfonic acid (PFSA) ionomer and 3D-ordered electrodes have imparted PEMFCs with boosted power density. To achieve the compacted stack target of 6 kW/L or above for the wide commercialization of FCVs, developing available cathodes for high-power-density operation is critical for the PEMFC. However, current developments still remain extremely challenging with respect to highly active and stable catalysts in practical operation, controlled distribution of ionomer on the catalyst surface for reducing catalyst poisoning and oxygen penetration losses and 3D (three-dimensional)-ordered catalyst layers with low Knudsen diffusion losses of oxygen molecular. This review paper focuses on impacts of the cathode development on automotive fuel cell systems and concludes design directions to provide the greatest benefit.

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Micro Galvanic Cell To Generate PtO and Extend the Triple-Phase Boundary during Self-Assembly of Pt/C and Nafion for Catalyst Layers of PEMFC

Cited by 14 publications

References 17 publications

Synthesis of highly dispersed Pt nanoparticles into carbon supports by fluidized bed reactor atomic layer deposition to boost PEMFC performance

Synthesis of highly dispersed Pt nanoparticles into carbon supports by fluidized bed reactor atomic layer deposition to boost PEMFC performance

Electrochemical study of temperature and Nafion effects on interface property for oxygen reduction reaction

Cathode Design for Proton Exchange Membrane Fuel Cells in Automotive Applications

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