On the conductivity of phosphoric acid electrolyte

Advanced Construction Materials for High Temperature Steam PEM Electrolysers

“…Since high temperature PEM cells are working at temperatures around 150°C, H 2 SO 4 cannot be used to simulate conditions in the 3-electrode cell, even at high concentration. Instead, concentrated H 3 PO 4 can ben used, which permits to work at temperatures as high as 150-160°C, depending on the composition [14]. However, it was noticed by Appleby and Van Drunen that the Tafel slopes for noble electrocatalysts are significantly higher in concentrated phosphoric acid than those for more diluted solutions, being the apparent cause of adsorption of electrolyte on the electrode surface [7].…”

Acid‐Functionalized Mesostructured Aluminosilica for Hydrophilic Proton Conduction Membranes

“…Similar conductivity maxima have been observed for homogeneous acid solutions and attributed to the beneficial effects of higher acid concentrations being offset by reduced local hydration effects [7] or increased viscous resistance to proton transport. [50] While the triflic acid species appear to be stably incorporated within the mesopore channels, enhanced stability and solvent-barrier properties are anticipated for grafted or larger molecular weight acidic filler species. The combination of enhanced hydrophilicity, robust mesostructured channels, and strong acid functionality imparts superior high temperature (> 135°C) proton conductivity properties to PFSA-aluminosilica-functionalized mesostructured silica films, compared to Nafion 117 ® .…”

Ab InitioMolecular-Dynamics Simulation of Concentrated Phosphoric Acid

“…1,2) Moreover, in spite of its high viscosity, liquid phosphoric acid has high proton conductivity, which makes it useful as fuel cell electrolytes. Therefore, many experimental and theoretical studies have been carried out on the liquid phase [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] as well as on the monomer [21][22][23] ( Fig. 1), crystal, [24][25][26] and the polymeric gels [27][28][29][30] of phosphoric acid.…”