Quantum jumps in the PEMFC science and technology from the 1960s to the year 2000 Part I. Fundamental scientific aspects

Proton exchange membrane fuel cells are at present in the forefront of all types of fuel cells because of the 'quantum jumps' in, its technology since its application in the 1960s, in NASAs Gemini space flights as an auxiliar y power source. PEMFC technology since the. 1960s highlights the 'quantum j umps' both, in the fundamental areas of research (Part I), and in the engin eering and technology and developmental (Part II), which are leading to the era of promising applications. This part of the review is on the 'quantum jumps' in the fundamental areas of research, which have enabled the rapid a dvances in the technology development, i.e. (i) transition from polystyrene sulfonic acid to perfluorosulfonic acid membranes; (ii) a 10- to 100-fold reduction in the platinum loading in electrode by using nanosize electrocat alyst particles supported on high surface area carbon and impregnation of t he proton conducting electrolyte into the active layer of the electrode; (i ii) optimization of structure of electrode and of membrane and electrode as sembly to enhance power densities to 0.5-0.7 W cm(-2) at desirable efficien cies; (iv) using perfluorosulfonic acid membranes for DMFCs instead of liqu id electrolytes to attain reasonably good efficiencies and power densities. The vital scientific challenges needing resolution for further advances in the technology are also summarized. (C) 2001 Elsevier Science B.V. All rig hts reserved.