Relative-Humidity Dependence of Electrochemically Active Surface Area in Porous Carbon Catalyst Layers

被引:4
作者
Chowdhury, Anamika [1 ,2 ]
Radke, Clayton J. [1 ]
Weber, Adam Z. [2 ]
机构
[1] Univ Calif Berkeley, Dept Chem & Biomol Engn, Berkeley, CA 94720 USA
[2] Lawrence Berkeley Natl Lab, Energy Technol Area, Berkeley, CA 94720 USA
关键词
FUEL-CELL CATALYST; OXYGEN REDUCTION REACTION; WATER-ADSORPTION; TRANSPORT RESISTANCES; MOLECULAR SIMULATION; MODELING TRANSPORT; EQUIVALENT-WEIGHT; ADSORBED WATER; IONIC LIQUIDS; IONOMER;
D O I
10.1149/1945-7111/ad09fc
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
Polymer-electrolyte fuel cells (PEFCs) utilize porous catalyst layers (CLs) formed of carbon supports on which Pt particles are deposited and ionomer films are distributed. Carbon supports themselves have varying degrees of porosity, where high-surface-area carbon (HSC) supports possess nanometer-sized interior pores that are suitable for Pt nanoparticle deposition but prevent deleterious ionomer penetration. However, this requires protons to transport through water pathways inside the pores. To understand the generation of such pathways, we examine the various mechanisms of water uptake by PEFC CLs, and the subsequent impact of water uptake on Pt utilization through developing a multiphysics model of the water wetting phenomena as a function of relative humidity. The model details water uptake via ionomer absorption, capillary condensation in the hydrophilic pores, and surface adsorption using molecular potential that account for various water and surface dipole interactions. The results quantify how mesoporous carbons with highly hydrophilic pores increase Pt utilization through the development of wetted layers, which at the same time enable optimized gas-transport pathways. It also demonstrates the impact of pore-size distribution (PSD) and physical and chemical parameters on the water uptake phenomena, allowing for future CL particle and structure optimization.
引用
收藏
页数:10
相关论文
共 81 条
[1]   Revealing the role of ionic liquids in promoting fuel cell catalysts reactivity and durability [J].
Avid, Arezoo ;
Ochoa, Jesus Lopez ;
Huang, Ying ;
Liu, Yuanchao ;
Atanassov, Plamen ;
Zenyuk, Iryna, V .
NATURE COMMUNICATIONS, 2022, 13 (01)
[2]   Experimental methods in chemical engineering: specific surface area and pore size distribution measurements-BET, BJH, and DFT [J].
Bardestani, Raoof ;
Patience, Gregory S. ;
Kaliaguine, Serge .
CANADIAN JOURNAL OF CHEMICAL ENGINEERING, 2019, 97 (11) :2781-2791
[3]   Probing Ionomer Interactions with Electrocatalyst Particles in Solution [J].
Berlinger, Sarah A. ;
McCloskey, Bryan D. ;
Weber, Adam Z. .
ACS ENERGY LETTERS, 2021, 6 (06) :2275-2282
[4]   Molecular Dynamics Study of Thermally Augmented Nanodroplet Motion on Chemical Energy Induced Wettability Gradient Surfaces [J].
Chakraborty, Monojit ;
Chowdhury, Anamika ;
Bhusan, Richa ;
DasGupta, Sunando .
LANGMUIR, 2015, 31 (41) :11260-11268
[5]  
Chowdhury A., 2019, ECS Transactions, V92, P247, DOI 10.1149/09208.0247ecst
[6]   Transport Resistances in Fuel-Cell Catalyst Layers [J].
Chowdhury, A. ;
Radke, C. J. ;
Weber, A. Z. .
POLYMER ELECTROLYTE FUEL CELLS 17 (PEFC 17), 2017, 80 (08) :321-333
[7]   Linking Perfluorosulfonic Acid Ionomer Chemistry and High-Current Density Performance in Fuel-Cell Electrodes [J].
Chowdhury, Anamika ;
Bird, Ashley ;
Liu, Jiangjin ;
Zenyuk, Iryna, V ;
Kusoglu, Ahmet ;
Radke, Clayton J. ;
Weber, Adam Z. .
ACS APPLIED MATERIALS & INTERFACES, 2021, 13 (36) :42579-42589
[8]   Calculation of contact angles from surfactant adsorption isotherms [J].
Chwastiak, Stephen .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2009, 339 (01) :196-201
[9]   Melting transition of confined Lennard-Jones solids in slit pores [J].
Das, Chandan K. ;
Singh, Jayant K. .
THEORETICAL CHEMISTRY ACCOUNTS, 2013, 132 (04) :1-13
[10]   Adsorptive characterization of porous solids: Error analysis guides the way [J].
De Lange, Martijn F. ;
Vlugt, Thijs J. H. ;
Gascon, Jorge ;
Kapteijn, Freek .
MICROPOROUS AND MESOPOROUS MATERIALS, 2014, 200 :199-215