scholarly journals Influence of Cathode Catalyst Layer with SiO2-Coated Pt/Ketjen Black Catalysts on Performance for Polymer Electrolyte Fuel Cells

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1517
Author(s):  
Kayoung Park ◽  
Masaki Goto ◽  
Magnus So ◽  
Sakae Takenaka ◽  
Yoshifumi Tsuge ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Proton Conductivity ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Pt Catalyst ◽  
Cathode Catalyst ◽  
Carbon Supports ◽  
Sio2 Coating ◽  
Cathode Catalyst Layer

In this study, we investigated the effect of silica (SiO2) layer included in a cathode catalyst layer (CL) on the performance for polymer electrolyte fuel cells (PEFCs). Porous carbons such as Ketjen black (KB) have been widely used as a support for Pt catalysts in PEFCs. Such KB-supported Pt catalyst (Pt/KB) was used as a cathode CL with low ionomer content (a condition of low proton conductivity). The Pt/KB was then coated with SiO2. In addition, the Pt/KB and SiO2-coated Pt/KB (SiO2-Pt/KB) were measured and analyzed under relative humidity (RH) conditions (100% and 20%). The catalyst ink of SiO2-Pt/KB showed higher stability and dispersion compared to Pt/KB, due to the hydrophilic surface characteristics of SiO2, which act as a binder-like ionomer. The performance of the SiO2-Pt/KB at 100% RH, was significantly lower than that of Pt/KB, whereas the performance of the Pt/KB at 20% RH, was significantly improved by SiO2 coating. This is due to an increase in the proton conductivity, which can be attributed to the hydrophilic properties of SiO2. Based on these results, the effect of SiO2 coating on performance, depending on carbon supports of SiO2-coated Pt/Carbon catalysts, could be evaluated.

Fabrication of Cathode Catalyst Layer By Use of Multi-Nozzle Electrospray Method on Polymer Electrolyte Fuel Cells

2021 ◽  
Vol MA2021-02 (37) ◽  
pp. 1087-1087
Author(s):  
Makoto Uchida ◽  
Kayoko Tamoto ◽  
Takumi Nagasaka ◽  
Chihiro Taguchi ◽  
Shimao Yoneyama
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Cathode Catalyst ◽  
Cathode Catalyst Layer

Effectiveness factor of Pt utilization in cathode catalyst layer of polymer electrolyte fuel cells

2008 ◽  
Vol 86 (7) ◽  
pp. 657-667 ◽  
Author(s):  
Zetao Xia ◽  
Qianpu Wang ◽  
Michael Eikerling ◽  
Zhongsheng Liu
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Effectiveness Factor ◽  
Cathode Catalyst ◽  
Catalyst Layers ◽  
Effectiveness Factors ◽  
Cathode Catalyst Layer ◽  
Pt Utilization

In this work, we analyze effectiveness factors of Pt utilization in perfluorosulfonate ionomer (PFSI) bonded thin film cathode catalyst layers of polymer electrolyte fuel cells. We define the effectiveness factor of Pt utilization as the apparent rate of current conversion exhibited by a specific catalyst layer design divided by the ideal rate obtained if all Pt atoms were used equally in electrochemical reactions at the specified electrode overpotential and externally provided reactant concentrations. This definition includes statistical factors at all relevant scales as well as non-uniformities of reaction rate distributions under operation. Our model is based on the random composite agglomerated morphology of the catalyst layer. It accounts for the interplay of transport phenomena and electrochemical kinetics. At the mesoscopic scale, limited effectiveness of Pt utilization in agglomerates is mainly an electrostatic effect. We determined spatial distributions of effectiveness factors of agglomerates in the through-plane direction, and thereafter calculated overall effectiveness factors of the cathode catalyst layer. Our results show that small agglomerate radius, low operating current density, high operating temperature, and high oxygen partial pressure result in high effectiveness factors of Pt utilization. Finally, we compared PFSI-bonded thin film cathode catalyst layers with ultrathin two-phase cathode catalyst layers in terms of effectiveness factors. Including the surface to volume atom ratio of Pt nanoparticles, the two different types of structures exhibit similar effectiveness factors of Pt utilization, which are found to be distinctly below 10%.Key words: polymer electrolyte fuel cells, fuel cell modeling, cathode catalyst layer, Pt utilization, effectiveness factor.

Thinning of Cathode Catalyst Layer in Polymer Electrolyte Fuel Cells Due to Foreign Cation Contamination

2018 ◽  
Vol 165 (6) ◽  
pp. F3015-F3023 ◽  
Author(s):  
Charles J. Banas ◽  
Md. Aman Uddin ◽  
Jaehyung Park ◽  
Leonard J. Bonville ◽  
Ugur Pasaogullari
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Cathode Catalyst ◽  
Cathode Catalyst Layer ◽  
Foreign Cation
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