Oxygen reduction kinetics at ambient temperature is more rapid in alkaline electrolytes than in acid electrolytes, and the use of non-noble electrocatalysts, in the same conditions, is feasible. However, a major disadvantage of AFCs is that alkaline electrolytes, such as NaOH or KOH, react with CO2 to precipitate carbonates. The main consequence of that side reaction is that AFCs are currently restricted to specialized applications where pure H2 and O2 are utilized. AFCs have therefore been considered appropriate for small power aerospace and defense applications, but their use in commercial applications has so far been limited. A schematic description of the components in an AFC is shown here:
Funding for development and of demonstration projects for the AFC are substantially smaller than for the other fuel cell technologies. These fuel cells are not really competitive for the production of power in stationary power plants or terrestrial electric vehicles, mostly because of the high sensitivity of their performance on the presence of carbon di.