Phosphonated mesoporous silica based composite membranes for high temperature proton exchange membrane fuel cells

Phosphonate poly(vinylbenzyl chloride)-Modified Sulfonated poly(aryl ether nitrile) for Blend Proton Exchange Membranes: Enhanced Mechanical and Electrochemical Properties

“…The use of chloromethylated SEBS polymers is particularly advantageous, as the steric hindrance of the benzyl chloride block is minimal, which makes it easier to react with TEP and prepare proton membranes with high degrees of phosphorylation. These findings suggest that the preparation of proton exchange membranes with improved hydrolysis stability is possible through the use of phosphorylated polymers [30,31].…”

“…However, it has been observed that the hydrolysis stability of C-O-P and Si-O-P bonds is poor compared to that of C-P bonds [26]. To address this issue, a phosphorylated polymer can be obtained by reacting a chloromethylated aromatic polymer with triethyl phosphite (TEP), which can then be hydrolyzed under acidic conditions to obtain the desired phosphoric-type polymer [28][29][30][31]. The use of chloromethylated SEBS polymers is particularly advantageous, as the steric hindrance of the benzyl chloride block is minimal, which makes it easier to react with TEP and prepare proton membranes with high degrees of phosphorylation.…”

Overcoming the Electrode Challenges of High-Temperature Proton Exchange Membrane Fuel Cells

“…Phosphonated mesoporous silica-based composite membranes have also been explored. These membranes benefit from a high density of ion exchange groups in the composite membrane and the mesoporous morphology of the fillers to conduct protons above 100 °C [79]. Furthermore, promising results have been achieved by using composite membranes based on a phosphotungstic acid (PWA)-doped polyethersulfone-PVP (PES-PVP) matrix for HT-PEMFCs [80].…”

A phosphonated phenol-formaldehyde-based high-temperature proton exchange membrane with intrinsic protonic conductors and proton transport channels

“…For commercial applications, PEMs should satisfy such requirements as mechanical and oxidative stability, superior proton conductivity, higher power density and long-term stability. 5 At present, phosphoric acid (PA) doped polybenzimidazole (PBI) is being widely investigated for HT-PEMs, on account of its satisfactory performance in the temperature range from 100 to 200 C. In order to obtain high proton conductivity, many studies have been undertaken to promote the acid uptake of HT-PEMs either through adding proton carriers (e.g., imidazole, 6,7 pyridine 8 ) or by increasing the concentration of protonic charge carriers (e.g., sulfonic acid groups, 9,10 carboxylic acid, 11 phosphoric acid groups [12][13][14][15] ). In general, PA-doped HT-PEMs contain immobilized PA and free PA. Immobilized acid molecules are believed to donate protons to the basic sites, and to be immovable polymer parts, while the free acid involved in the polymer volume contributes to long-range proton transport.…”

“…, imidazole, 6,7 pyridine 8 ) or by increasing the concentration of protonic charge carriers ( e.g. , sulfonic acid groups, 9,10 carboxylic acid, 11 phosphoric acid groups 12–15 ). In general, PA-doped HT-PEMs contain immobilized PA and free PA. Immobilized acid molecules are believed to donate protons to the basic sites, and to be immovable polymer parts, while the free acid involved in the polymer volume contributes to long-range proton transport.…”