title: Development of cesium phosphotungstate salt and chitosan composite membrane for direct methanol fuel cells.
abstract: A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3-xPW12O40 (0≤x≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x=2 and Cs2-PTA content of 5 wt%. The value is 6×10(-3) S cm(-1) and 1.75×10(-2) S cm(-1) at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6×10(-7), 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1×10(4)/Scm(-3)s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells.
authors.affiliation: Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing, 100191, PR China.
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Xiao
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiang
authors.forename: Ruijie
authors.initials: R
authors.lastname: Xiu
authors.forename: Shanfu
authors.initials: S
authors.lastname: Lu
mesh_terms: D002586:Cesium / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D004553:Electric Conductivity; D011211:Electric Power Supplies; D055595:Mechanical Phenomena; D008567:Membranes, Artificial; D000432:Methanol / Q000737:chemistry*; D010539:Permeability; D017553:Phosphorus Compounds / Q000737:chemistry*; D011522:Protons; D012492:Salts / Q000737:chemistry; D013696:Temperature; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D017553:Phosphorus Compounds; D011522:Protons; D012492:Salts; D017973:Tungsten Compounds; D002586:Cesium; D048271:Chitosan; C045951:tungstate; D000432:Methanol
keywords: Alternative proton exchange membranes; CTS; CTS/Cs(x)PTA; Cesium phosphotungstate salt; Chitosan; Cs(x)PTA; Direct methanol fuel cells; FID; GC; HPAs; Methanol crossover; NPs; P; PTA; S(dry); S(wet); W(dry); W(wet); WU; area of the dry membrane; area of wet membrane; cesium phosphotungstate salt (0≤x≤3); cesium phosphotungstate salt and chitosan composite membrane; chitosan; gas chromatography; heteropolyacids; hydrogen flame ionization; methanol diffusion coefficient; nanoparticles; phosphotungstate salt; proton conductivity; selectivity factor; swelling degree; water uptake; weight of dry membrane; weight of wet membrane; ΔS; σ; φ