sulfonated poly (ether ether ketone) (speek) with a low degree of sulfonation (ds = 40%) was prepared for proton exchange membrane fuel cells (pemfc). poly (ether ether ketone) (peek) was sulfonated in concentrated h2so4 under n2 atmosphere and characterized by the hydrogen nuclear magnetic resonance (h-nmr) technique. after preparation of the speek polymer, the obtained polymer was dissolved i...

Although they hold the promise of clean energy, state-of-the-art fuel cells based on polymer electrolyte membrane fuel cells are inoperable above 100 degrees C, require cumbersome humidification systems, and suffer from fuel permeation. These difficulties all arise from the hydrated nature of the electrolyte. In contrast, "solid acids" exhibit anhydrous proton transport and high-temperature sta...

We report 1H-1,2,3-triazole as an active group to dramatically enhance proton conduction in a polymer electrolyte membrane (PEM). The conductivities of a poly(4-vinyl-1H-1,2,3-triazole) membrane without any acidic dopants are about 105 times greater than those of poly(4-vinylimidazole) in dry air at 50-150 degrees C. Polymers with groups promoting proton conduction attached to the backbone have...

Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a...

We investigated the time-dependent self-diffusion coefficients of water, , in polymer electrolyte membranes at 278 K. The was measured from 0.7 to 100 ms by field gradient NMR techniques. The results showed that the self-diffusion coefficients of water were dependent on less than 2 ms due to restricted diffusion, and were constant beyond 3 ms. The tortuosity and surface-to-volume ratio related ...

Inorganic-organic composite electrolyte membranes were fabricated from CsXH3-XPMo12O40 (CsPOMo) and quaternary diazabicyclo-octane polysulfone (QDPSU) using a polytetrafluoroethylene (PTFE) porous matrix for the application of intermediate temperature fuel cells. The CsPOMo/QDPSU/PTFE composite membrane was made proton conducting by using a relatively low phosphoric acid loading, which benefits...

Abstract. Proton exchange membrane (PEM) electrolysis is one of the waters splitting techniques available for producing green hydrogen. As such, improvement ion conductivity will result in hydrogen production. Ionic liquids have recently been reported to enhance ionic PEM. Herein, a screening method select suitable development efficient proton membrane. COnductor-like Screening MOdel Realistic ...

proton exchange membrane fuel cells (pemfcs) are electrochemical devices that show the highest power densities compared to the other type of fuel cell. in this work, nanocomposite membranes used for proton exchange membrane fuel cells as poly(vinyl alcohol)/la2ce2o7 (pva-lc) with the aim of increasing the water uptake and proton conductivity. glutaraldehyde (ga) was used as cross linking agent ...