01784nas a2200241   4500008004100000022001400041245010000055210006900155260012900224300001200353490000600365520087700371653003301248653002601281653000901307100001801316700001601334700001401350700001601364700001501380700001601395856013101411       2006                        eng d  a1550-624X00aAnalysis of single PEM fuel cell performances based on current density distribution measurement0 aAnalysis of single PEM fuel cell performances based on current d  aTHREE PARK AVE, NEW YORK, NY 10016-5990 USAbUniv Perugia; Italian Agcy New Technol & Environm; Amer Soc Mech EngineerscAUG  a351-3570 v33 a<p>A new in situ measurement method of mapping the current density distribution in polymer electrolyte fuel cells (PEFC) is used to analyze the performance of a fuel cell under different operating conditions. The present method is useful in investigating the current density distribution in a single cell as well as a stack, which carries the information about the local reactant activity over the electrode area It was found that the current density close to the gas inlets is strongly influenced by the reactants' relative humidity. The performance close to the gas outlets is greatly influenced by the inlet gas pressures and the stoichiometry factors of the reactant gases, mainly on the cathode side. It was also observed that the performance of the fuel cell drops with the increase in operating temperature if the reactant gases are not sufficiently humidified.</p>10acurrent density distribution10afuel cell performance10aPEFC1 aGhosh, P., C.1 aWuester, T.1 aDohle, H.1 aKimiaie, N.1 aMergel, J.1 aStolten, D.  uhttps://library.ncl.res.in/content/analysis-single-pem-fuel-cell-performances-based-current-density-distribution-measurement-002108nas a2200229   4500008004100000022001400041245007500055210006900130260010600199300001400305490000700319520130400326653000901630653001501639653003601654653002101690653001701711100001401728700001501742700001801757856010301775       2007                        eng d  a0013-468600aDMFC at low air flow operation: study of parasitic hydrogen generation0 aDMFC at low air flow operation study of parasitic hydrogen gener  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a6060-60670 v523 a<p>In this paper, the effect of hydrogen generation in direct methanol fuel cells (DMFC) is described. Under certain operating conditions hydrogen generation occurs in DMFC causing an additional methanol consumption and a decrease of the cell voltage. For the present experiments a segmented cell with an active area of 244 cm 2 is used. The cell has 196 segments which are regularly distributed on the whole area. By this experimental setup hydrogen generation was found in regions with insufficient air supply. Hydrogen generation was analyzed by systematically applying different air flow rates and detecting the local current densities. The theory for hydrogen generation is confirmed by the results obtained from the segmented cell. A correlation between open circuit voltage (OCV), air flow rate and hydrogen generation was observed. Furthermore, half-cell measurements with different methanol concentrations were performed and used for analyzing the processes during hydrogen generation. The work clearly indicates the importance of sufficient cathode air supply for DMFC. Starved cathode areas not only do not contribute to the overall current generation but in addition reduce the power and efficiency by the parasitic generation of hydrogen. (C) 2007 Elsevier Ltd. All rights reserved.</p>10aDMFC10aEfficiency10aelectrolytic hydrogen evolution10aoxygen depletion10aside-effects1 aDohle, H.1 aMergel, J.1 aGhosh, P., C.  uhttps://library.ncl.res.in/content/dmfc-low-air-flow-operation-study-parasitic-hydrogen-generation