کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1288286 1498005 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modelling the water distribution within a hydrophilic and hydrophobic 3D reconstructed cathode catalyst layer of a proton exchange membrane fuel cell
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Modelling the water distribution within a hydrophilic and hydrophobic 3D reconstructed cathode catalyst layer of a proton exchange membrane fuel cell
چکیده انگلیسی

We reconstruct a section of the cathode catalyst layer (CCL) of a Gore PEMFC membrane electrode assembly three-dimensionally with nanometre scale resolution. Subsequently, we present a new modelling method to fill the pore space of this matrix stepwise with water, enabling the description of varying saturation conditions of the CCL. The method is based on a 3D pore size distribution and enables to differentiate between a hydrophilic and a hydrophobic CCL. It utilizes a sequence to fill the pores according to their size, going from small to large (hydrophilic) or vice versa (hydrophobic), until a predefined value of water saturation is reached. We compare both cases by calculating an effective diffusivity for oxygen in nitrogen in all spatial directions. Both the hydrophilic and the hydrophobic case display a similar ability to transport oxygen up to approximately 50% water saturation of the pore space. At higher water saturation, we calculate larger diffusivity values for the hydrophobic case. Finally, we calculate the specific reaction surface area that is accessible from the gas diffusion layer via unfilled pores for all water saturation conditions. At 50% saturation, the hydrophobic case displays a twenty times larger reaction surface area than the hydrophilic case.


► We image, segment and reconstruct a commercial Gore cathode catalyst layer.
► We introduce a method to partially or totally fill the pore space with water.
► We differentiate between a hydrophilic and hydrophobic pore space.
► The method is based on the pore size distribution of the pore space.
► We use the model to calculate parameters accessible surface area and diffusivity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 227, 1 April 2013, Pages 260–266
نویسندگان
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