ABSTRACT
Proton-exchange membrane fuel cells, also known as polymer electrolyte membrane fuel cells (PEMFC), are the type mainly used for transport applications. Fuel cells produce electricity through the reaction of a fuel with oxygen. Hydrogen-oxygen fuels cells use hydrogen as the fuel. The energy of oxidation of conventional fuels can be converted directly into electricity in a fuel cell. The maximum theoretical energy efficiency of a fuel cell operating at low power density, using pure hydrogen and oxygen and without additional energy capture is 83%. Many combinations of fuel and oxidant can be used for fuel cells. Though hydrogen and oxygen as a combination is conceptually simple, hydrogen has some practical difficulties, including that it is a gas at standard temperature and pressure. Fuel cells have also been developed to run on methanol. There are two basic types of fuel cell that use this fuel: reformed methanol fuel cell (RMFC) and direct methanol fuel cell (DMFC).
