Enhanced Triple-Phase Interface in PEMFC by Proton Conductor Absorption on the Pt Catalyst

Abstract

In a proton exchange membrane fuel cell (PEMFC), the membrane electrode assembly (MEA) is the core component and the region of the oxidation−reduction. In order to obtain a great performance, Pt with excellent catalyst efficiency is usually adopted in PEMFC as the catalyst. However, the high cost and poor durability remain the two major challenges in the application of PEMFC; thus, it is worth paying attention to enhance the utilization of the Pt catalyst and the stability of PEMFC. In this work, the Nafion array membrane with a larger specific surface and higher proton conductivity was applied to the cathode catalyst layer (CL) to prepare the ordered MEA. In order to improve the three-phase interface of the cathode CL, Nafion was adsorbed on the Pt particles as the proton conductor to expedite the proton transfer efficiency based on the principle that sulfonic acid is easily adsorbed on the Pt surface. In this case, the peak power density of PEMFC with Nafion absorption on the Pt surface is up to 843 mW cm −2 at the Pt loading of 61.4 μg cm −2 , which is much higher than that of the fuel cell without a proton conductor on the Pt catalyst in the cathode CL (710 mW cm −2 ). Besides, the durability tests show that PEMFCs with Nafion absorption on the Pt catalyst surface can work continuously for 100 h without obvious voltage attenuation, which is more stable than that of the bare Pt for 70 h. In conclusion, Nafion as the proton conductor was adsorbed on the Pt catalyst surface of the cathode CL to enhance the triple-phase interface in PEMFC, which is expected to be a universal method to prepare PEMFCs with high stability and peak power density at a low preparation cost.

Nanosized Proton Conductor Array with High Specific Surface Area Improves Fuel Cell Performance at Low Pt Loading

“…The choice of Nafion array height at 1.5 μm is based on three reasons. First, our previous works have shown that fuel cells with a cone Nafion array height of 1.3 μm exhibit optimal performance in both the anode and cathode. , Second, we optimized the fuel cells performance with different Nafion array heights under a constant diameter of 400 nm and found that the fuel cell with an array height of 1.5 μm obtains optimal performance when the height of the Nafion array varies from 0.5 to 2.5 μm (Figure S7). Third, to focus on the effect of Nafion array size ( i .…”

“…The accumulation of hydrogen becomes difficult to vent and can cause a highpressure hydrogen bulge on the surface, leading to damage to the 3 μm exhibit optimal performance in both the anode and cathode. 48,49 Second, we optimized the fuel cells performance with different Nafion array heights under a constant diameter of 400 nm and found that the fuel cell with an array height of 1.5 μm obtains optimal performance when the height of the Nafion array varies from 0.5 to 2.5 μm (Figure S7). Third, to focus on the effect of Nafion array size (i.e., the diameter of the Nafion pillar), the height of the Nafion array was maintained at 1.5 μm, while the diameter of the Nafion pillars was varied.…”

Pt Nanoparticles Supported on Iron and Nitrogen-Doped Holey Graphene for Boosting ORR Performance

“…1,2 However, the sluggish kinetics of the halfcell reaction is a significant challenge in improving the performance of fuel cell devices. 3 Catalysts play a critical role in overcoming this challenge by lowering the activation energy barrier of the oxygen reduction reaction (ORR). Although Ptbased materials remain the most practical catalysts for the ORR, the high cost and scarcity of Pt hinder its widespread application in fuel cells.…”

“…Fuel cells are a promising technology for generating clean and efficient energy. , However, the sluggish kinetics of the half-cell reaction is a significant challenge in improving the performance of fuel cell devices . Catalysts play a critical role in overcoming this challenge by lowering the activation energy barrier of the oxygen reduction reaction (ORR).…”

In Situ Flame-Synthesized Carbon Nanotubes on Carbon Paper as a Microporous Layer for Proton Exchange Membrane Fuel Cells

“…Proton exchange membrane fuel cell (PEMFC) is the most promising fuel cell because it can start quickly, work at low temperature, and output a high power density. − Gas diffusion layer (GDL) is one of the key components of PEMFC, , as it can transfer electrons from the catalyst layer to the bipolar plates, allow the reactant gases to reach the catalyst through it for electrochemical reaction, and remove the excess water produced at the cathode side. GDL is composed of a gas diffusion substrate and a microporous layer (MPL). , MPL provides support to the catalyst layer, adjusts the pore structure of GDL, and reduces the contact resistance between the catalyst layer and gas diffusion substrate. − …”