اثر ساختار مايعات يوني بر روي عملكرد كاتاليست آند پيل سوختي متانولي مستقيم

چكيده انگليسي :

79 Effect of ionic liquids structure on the performance of DMFC anode catalyst Majid Sedighi M Sedighi@ch iut ac ir 2011 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Mohamad Zhiani m zhiani@cc iut ac ir Behzad Rezaie rezaei@cc iut ac ir Abstract Direct methanol fuel cell DMFC is being widely investigated and considered as a prospective andpotential power source for the application in transportation portable electronics residential power sources etc because of its high energy conversion efficiency low operation temperature and low pollution to theenvironment easy handle However DMFC still has some problems that need to be solved At the presenttime the most important disadvantages for DMFC are the reduce kinetics at the electrodes mainly at theoxygen electrode the sensitivity of the electrodes to carbon monoxide poising and low operatingtemperature that lead to need high Pt catalyst and high cost Thus studying on the disadvantages removal ofDMFC is an important subject One method for enhancing the performance of liquid type fuel cell is theadding of additives Different additives may be employed to perform different functions such as reducingCO poising of the catalyst increasing wet ability of the electrodes or removing dissolved oxygen andimpurities in the fuel cell In recent years utilization of ionic liquids ILs as electrolyte additives andmembrane modifies is considered as a new topic in studies of batteries and fuel cells ILs are molten saltsresulting from the combination of organic cations and various anions Over the past few years these ILs havegenerated much attention They are non volatile and non flammable have high thermal stability Consideringtheir electrochemical properties ILs have electrochemical windows that are much greater than those foraqueous electrolytes Because of these unique properties ILs applicable in many electrochemical devicessuch as Li ion batteries super capacitors solar cells fuel cells and as additive in lead acid batteryelectrolytes In the present work for the first time the effects of four ILs as a fuel additive were studied inDMFC A family of alkylammonium hydrogen sulfate ILs which are different in the number of alkyl chain is investigated with the aim to compare effects of their structure on the electrochemical behavior of methanolelectrooxidaton Effect of ILs structure on the performance of DMFCs anode has been studied by differentelectrochemical methods such as cyclic voltammetry CV Chronoamperometric CA linear sweepvoltammetry LSV electrochemical impedance spectroscopy EIS The results show that with increasing ofalkyl chain of ILs cation the electroactivity of catalyst decrease in methanol oxidation reaction related tobeetle active sites of catalyst by cation of ILs A possible explanation is that with increasing the number ofalkyl chain bulk resistance increased and proton transfer to the catalyst surface decreases as well Finally byanalyzing test results it could be concluded at low temperature ILs does not have any promising effect on thecatalyst activity Keyword Direct methanol fuel cell Methanol electrooxidation Ionic liquid Alkylammonium hydrogensulfate

صديقي، مجيد

اثر ساختار مايعات يوني بر روي عملكرد كاتاليست آند پيل سوختي متانولي مستقيم

الكترواكسيداسيون متانول , آلكيل آمونيوم هيدروژن سولفات