an essential requirement for an operating pem fuel cell is providing proper water content in the membrane. to avoid water flooding an appropriate water balance is required. here, an analytic model of a planar membrane humidifier for pem fuel cell is proposed where the effect of dimensional parameters includes membrane thickness, membrane area and channel hydraulic diameter are investigated. a n...

Dynamic and steady-state water flux, current density, and resistance across a Nafion 115 membrane-electrode-assembly (MEA) were measured as functions of temperature, water activity, and applied potential. After step changes in applied potential, the current, MEA resistance, and water flux evolved to new values over 3000-5000 s, indicating a slow redistribution of water in the membrane. Steady-s...

The V-type H(+)-ATPase is thought to provide the driving force for transepithelial electrolyte and fluid secretion in Malpighian tubules. To confirm the presence of this proton pump in Malpighian tubules of the yellow fever mosquito Aedes aegypti, we used several antibodies raised against the V-type H(+)-ATPase of Manduca sexta. Western blot analysis confirmed the presence of the V-type H(+)-AT...

The design of a non-precious metal oxygen reduction reaction (ORR) catalyst of high activity and long durability in acidic electrolyte is of great importance for the development and commercialization of low-temperature fuel cells, which remains a great challenge to date. Here, we demonstrate a facile, scalable protocol for the controlled synthesis of CoxC encapsulated in carbon nanotubes as a n...

The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recov...

Semiconducting-ionic conductors have been recently described as excellent electrolyte membranes for low-temperature operation solid oxide fuel cells (LT-SOFCs). In the present work, two new functional materials based on zinc oxide (ZnO)-a legacy material in semiconductors but exceptionally novel to solid state ionics-are developed as membranes in SOFCs for the first time. The proposed ZnO and Z...

A protonic ceramic fuel cell (PCFC) has great potential for medium temperature power generation. Its working process, however, is complicated and quite different from the traditional oxygen ionic solid oxide (O2?-SOFC) proton exchange membrane (PEMFC). In this paper, a multi-physical model PCFC with H+/e?/O2? mixed conducting cathode established, in which fuel- oxidant-diffusing processes; elec...

Advanced polymer composite membranes were prepared from a linear sulphonated poly(ether ether ketone) (SPEEK) with bismuth cobalt zinc oxide [BCZO, (Bi2O3)0.07(CoO)0.03(ZnO)0.90] nanopowder as an inorganic additive for the application of H2–O2 fuel cell. Morphological data tend to provide evidences incorporation BCZO into SPEEK polymer. Indeed, membrane loaded 7.5 wt.% was identified uptake max...