Research / 2020 / Article / Fig 3

Review Article

Advancement toward Polymer Electrolyte Membrane Fuel Cells at Elevated Temperatures

Figure 3

The proposed proton transportation on PWA-meso-silica in two ways. One is proton hopping on an isolated phosphotungstic acid, briefly as the intramolecular proton transfer pathway. The other is intermolecular proton transfer pathway, in which the proton-exchange process is composed of a series of “hops” among HPW or PWA molecules and water molecules along the hydrogen bond [76].