A protonic ceramic fuel cell or PCFC is a fuel cell based around a

ceramic A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...

, solid, electrolyte material as the proton conductor from

anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic ...

cathode A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction in wh ...

. These fuel cells produce electricity by removing an electron from a hydrogen atom, pushing the charged hydrogen atom through the ceramic membrane, and returning the electron to the hydrogen on the other side of the ceramic membrane during a reaction with oxygen. The reaction of many proposed fuels in PCFCs produce electricity and heat, the latter keeping the device at a suitable temperature. Efficient proton conductivity through most discovered ceramic electrolyte materials require elevated operational temperatures around 600-700 degrees Celsius, however intermediate temperature (200-400 degrees Celsius) ceramic fuel cells and lower temperature alternative are an active area of research. In addition to hydrogen gas, the ability to operate at intermediate and high temperatures enables the use of a variety of liquid hydrogen carrier fuels, including: ammonia, and methane. The technology shares the thermal and kinetic advantages of high temperature molten carbonate and

solid oxide fuel cell A solid oxide fuel cell (or SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel. Fuel cells are characterized by their electrolyte material; the SOFC has a solid oxide or ceramic electrolyte. A ...

s, while exhibiting all of the intrinsic benefits of proton conduction in

proton exchange membrane fuel cell A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

s (PEMFC) and

phosphoric acid fuel cell Phosphoric acid fuel cells (PAFC) are a type of fuel cell that uses liquid phosphoric acid as an electrolyte. They were the first fuel cells to be commercialized. Developed in the mid-1960s and field-tested since the 1970s, they have improved sig ...

s (PAFC). PCFCs exhaust water at the cathode and unused fuel, fuel reactant products and fuel impurities at the anode. Common chemical compositions of the ceramic membranes are barium zirconate (BaZrO3), cesium dihydrogen phosphate (CsH2PO4), and complex solid solutions of those materials with other ceramic oxides. The acidic oxide ceramics are sometimes broken into their own class of protonic ceramic fuel cells termed " solid acid fuel cells". Some PCFCs operate at high enough temperatures that fuels can be electrochemically oxidized at the anode, not needing the intermediate step of producing hydrogen through reforming process. In this setting, gaseous molecules of the hydrocarbon fuel are absorbed on the surface of the

in the presence of water vapor, with

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

as the primary reaction product; hydrogen atoms are efficiently stripped off to be turned into H+ ions then moving into the electrolyte to the other side (

) where they react with oxygen in the air to produce water. Other PCFCs operate at lower temperatures and utilize chemical catalysts in addition to electrochemical catalysts to produce hydrogen for the reduction reaction.

Applications and commercial development

PCFCs operating at intermediate temperature of 200 - 400 degrees Celsius have been proposed for heavy duty trucking. Remote power applications using PCFCs have been demonstrated at Canadian oil wells.

Applications and commercial development

See also

References

Further reading