Full Parametric Study of the Influence of Ionomer Content, Catalyst Loading and Catalyst Type on Oxygen and Ion Transport in PEM Fuel Cell Catalyst Layers

Abstract

To advance the technology of polymer electrolyte membrane fuel cells, material development is at the forefront of research. This is especially true for membrane electrode assembly, where the structuring of its various layers has proven to be directly linked to performance increase. In this study, we investigate the influence of the various ingredients in the cathode catalyst layer, such as ionomer content, catalyst loading and catalyst type, on the oxygen and ion transport using a full parametric analysis. Using two types of catalysts, 40 wt.% Pt/C and 60 wt.% Pt/C with high surface area carbon, the ionomer/carbon content was varied between 0.29–1.67, while varying the Pt loading in the range of 0.05–0.8 mg cm−2. The optimum ionomer content was found to be dependent on the operating point and condition, as well as catalyst loading and type. The data set provided in this work gives a starting point to further understanding of structured catalyst layers.

The product selectivity zones in gas diffusion electrodes during the electrocatalytic reduction of CO2

“…Nafion acts as a strong adhesive to introduce a mechanical stability to the catalytic layer, however, the ionomer distribution is a known issue in fuel cell research due to its influence on local reactant transportation and associated mass (oxygen) transport resistances. 38,39 Likewise, the transport of reactants in CO 2 RR towards the active sites should also be sensitive to the local distribution of the ionomer, acting as a barrier for the CO 2 and HCO 3 À transport.…”

Probing Ionomer Interactions with Electrocatalyst Particles in Solution

“…Indeed, carbon treatment methods to tune the PFSA/carbon interaction have been successfully employed to control CL performance. [53][54] Similarly, one metric often reported is the ionomer-to-carbon (I/C) ratio, where optimal ratios [55][56][57][58][59][60][61] seem dependent on carbon type; given the results herein, ideal ratios will also likely vary with solvent and EW. Additional Parameters.…”

“…Therefore, given the larger surface area of carbon relative to platinum in most electrocatalyst particles, PFSA/particle adsorption (and subsequent aggregation) in inks is likely dominated by the PFSA/carbon interaction. Indeed, carbon treatment methods to tune the PFSA/carbon interaction have been successfully employed to control CL performance. , Similarly, one metric often reported is the ionomer-to-carbon (I/C) ratio, where optimal ratios − seem dependent on carbon type; given the results herein, ideal ratios will also likely vary with solvent and EW.…”

Multi‐objective optimization of temperature uniformity in cathode catalyst layer and performance of PEMFC with an ionomer‐gradient design

“…In the present work, it is assumed that ionomer content cannot change the CL thickness, which has been confirmed in Ref.. 12 As a result, the CCL porosity decreases gradually towards the MEM/CCL interface due to the gradient reduction of ionomer content along the reverse direction. 13,14 Additionally, the change of ionomer content also affects the thickness of ionomer film coating the agglomerate.…”

“…In recent years, the design of the spatial distribution of ionomer in CCL has become a valuable selection to optimize the CCL structure. 9,[12][13][14][15][16] Alink et al 12 experimentally studied a full parametric study of various catalyst layer compositions. It was found that the optimum ionomer content is dependent on the operating load and gas relative humidity (RH).…”