Impact of Catalyst Ink Dispersing Solvent on PEM Fuel Cell Performance and Durability

Abstract

The dispersing solvent used for fuel cell catalyst ink preparation plays a vital role in establishing the resulting morphology of the electrode layers, which in turn will impact the performance of proton exchange membrane (PEM) fuel cells. In this study, we report the impact of various ionomer dispersion solvents on PEM fuel cell performance and durability; two aqueous (1-propanol/water and 2-propanol/water) and several non-aqueous dispersing solvents (ethylene glycol and 1,2-butanediol) are compared. The cathode catalyst layer (CCL) fabricated using inks prepared with 1-propanol/water (3:1, w/w) exhibited the best initial performance followed by the CCL prepared using ethylene glycol. The CCLs made from non-aqueous ethylene glycol and 1,2-butanediol exhibited the best durability upon accelerated stress testing. Scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy indicated that, after the stress test, the distribution of both the Nafion ionomer and Pt nanoparticles within the CCLs prepared with non-aqueous ionomer dispersions underwent less change than those prepared with aqueous dispersions, which is responsible for the improved durability.

Probing Ionomer Interactions with Electrocatalyst Particles in Solution

“…The side chain spacing defines the equivalent weight (EW, g of polymer/mol of SO 3 – ) . Many studies have characterized dried CLs to understand structure–property-performance relationships. − However, little is known about how to direct specific structures during manufacturing, which to date has been primarily empirical and thus nonpredictive. Enabling next-generation CLs and designing them a priori necessitates understanding the forces controlling formation and structure, especially the ionomer/particle interaction. , This ink-to-CL progression is depicted in Figure .…”

Toward the Continuous Production of Multigram Quantities of Highly Uniform Supported Metallic Nanoparticles and Their Application for Synthesis of Superior Intermetallic Pt-Alloy ORR Electrocatalysts

“…This can be attributed to either the less porous carbon support or a nonideal catalyst layer structure due to nonoptimized ink formulation. 62 For the sake of comparability, the same ink composition was used for all the different catalysts. An intensive examination of the impact of ink formulation and key rGO properties on the catalyst performance will be the subject of upcoming work.…”

“…However, at current densities >1 A cm –2 mass transport limitations start to affect the rGO supported electrocatalyst performance. This can be attributed to either the less porous carbon support or a nonideal catalyst layer structure due to nonoptimized ink formulation . For the sake of comparability, the same ink composition was used for all the different catalysts.…”

Towards a mechanically rechargeable solid fuel flow battery based on earth-abundant materials

“…200 mV, possibly due to reactant crossover causing mixed electrode potentials and / or catalyst poisoning. 30 To demonstrate repeatable performance and to explore the behavior of the reactor at different discharge conditions, we assembled a second cell operated at various current densities up to ca. 10 mA cm -2 .…”