Spectroscopic Study of Reinforced Cross-Linked Polymeric Membranes for Fuel Cell Application

Abstract

Acid-doped reinforced polymer electrolyte membranes for high-temperature polymer electrolyte membrane fuel cell applications (HT PEMFCs) are presented and spectroscopically studied. Fully aromatic polyethers are employed bearing main chain pyridine units as the proton accepting sites, which have two different substitution patterns of the pyridine units, namely, 2,5-or 2,6pyridine. This fact enables control of the solubility and of the acid doping ability of the polymeric membranes. Reinforcement is accomplished via incorporation of a PTFE woven fabric during the casting procedure for fabrication of the membranes. High acid uptake of the reinforced membranes was maintained for the 2,6-pyridine-based copolymers with high pyridine unit content. Studies of the swelling behavior of these reinforced membranes revealed that they expand mainly along the z-axis, which helps to avoid extensive damage in case of humidity or temperature changes during the fuel cell operation. Additionally, spectroscopic techniques are employed, namely, X-ray photoelectron spectroscopy, X-ray photoelectron spectroscopy with depth profile, near-edge X-ray absorption fine structure, and reflection electron energy loss spectroscopy, for the in-depth study of the two copolymer membranes doped with phosphoric acid. Through these spectroscopic evaluations, modifications in the membranes' chemical structure, orientation, composition, and electronic structure after the reinforcement and doping processes were elaborated and unveiled.

Titanium Dioxide/Phosphorous-Functionalized Cellulose Acetate Nanocomposite Membranes for DMFC Applications: Enhancing Properties and Performance

“…This test was assessed for 12 and 24 h by measuring the weight loss as presented in Table . The results illustrated that the nanocomposite membranes showed more stability after the addition of TiO 2 NPs owing to the role of TiO 2 in the interaction against the diffusion of H 2 O 2 …”

“…The results illustrated that the nanocomposite membranes showed more stability after the addition of TiO 2 NPs owing to the role of TiO 2 in the interaction against the diffusion of H 2 O 2 . 45 2.7. Contact Angle Analysis.…”

From orthophosphate to phosphine‐based groups: The effects of argon ion sputtering on doped polyethersulfone films

“…The data gathered here indicates that the CP membrane is less prone to react with the phosphoric acid and form the phosphine group. A probable reason for this is the chemical difference between both molecules, where CP has a bigger presence of hydrocarbon branches and crosslinks, whereas LP does not, as mentioned in a previous study 27 …”

“…A probable reason for this is the chemical difference between both molecules, where CP has a bigger presence of hydrocarbon branches and crosslinks, whereas LP does not, as mentioned in a previous study. 27 The atomic percentage of the two samples was taken from the survey spectra (the supplementary material contains the survey of both samples in 0 and 93 s as Figure S1) and can be seen in Table 2.…”

Low Temperature Water-Gas Shift: Enhancing Stability through Optimizing Rb Loading on Pt/ZrO2

“…Thus, the second stage is carried out at low temperatures (LT-WGS) with a highly active catalyst to achieve higher CO conversion. Polymer electrolyte membrane fuel cells (PEMFCs) are a heavily researched topic and an important technology for the future of renewable energy and portable power, as they have the potential to cleanly and efficiently provide electrical energy from hydrogen [1][2][3][4][5][6]. However, these PEMFCs are very susceptible to poisoning by CO, which is a product or byproduct of many hydrogen production reactions (e.g., steam reforming of hydrocarbons or alcohols).…”