Cationic contamination is known to cause performance degradation and reduced lifetime in polymer electrolyte based electrochemical systems. Calcium an important cationic impurity due its prevalence roadside particulates as airborne contaminant. The role of calcium ion (Ca2+) investigated in-situ by injecting a solution sulfate (CaSO4) deionized (DI) water into the cathode membrane (PEM) fuel cell through nebulizer. Stability tests are conducted determine effects at various current densities...

To correlate the cationic contaminant uptake of catalyst coated membrane (CCM) with polymer electrolyte fuel cell (PEFC) performance, CCMs were contaminated by saturating in varying concentrations H2SO4 and Al2(SO4)3 solution, establishing ex-situ equilibrium cation uptake. The then assembled tested single hardware to determine performance as a function contamination level. Smaller CCM coupons also saturated at same time full-size characterized acid site titration occupation fraction. It is...

The effect of trace amounts formic acid (HCOOH) in hydrogen fuel on proton exchange membrane cell (PEMFC) performance is reported. Long-term stability tests (100 h), periodic cyclic voltammetry scans, and electrochemical impedance spectroscopy analyses are used to evaluate characterize the effects this impurity performance. results show that HCOOH cause degradation significantly contaminate electrodes. Furthermore, full recovery from contamination could not be achieved by applying pure anode...

Water management is critical for achieving optimal performance and endurance of polymer-electrolyte membrane fuel cells. The authors conducted experiments cells using two water schemes: a solid plate (SP) approach water-transport (WTP) approach. In addition to constant-current hold tests at 1 A/cm2 investigate the voltage decay, diagnostic tests, i.e., polarization curves, hydrogen crossover, cathode cyclic voltammetry, fluoride emission, tensile stress-strain, are also cell material state...

Abstract The poly(butoxymethylenenorbornene‐ co ‐norbornenemethyl acetate) (PBN/NA) were successfully synthesized via the vinyl addition copolymerization of 2‐butoxymethylene norbornene (BN) and norbornene‐2‐methyl acetate (NA). ‐norbornenemethanol) (PBN/NOH) was obtained by de‐esterification PBN/NA. After doping with 4,5‐imidazole dicarboxylic acid (IDA) phosphoric (H 3 PO 4 ), proton exchange membranes crosslinked structure corresponding morphology, water uptake, conductivity, methanol...

The performance and durability of PEFCs were investigated by introducing HCl five different chloride salts into the air stream an operating fuel cell. Under same conditions at a constant 28.5 mM (Cl - ) concentration, cell degradation can be ranked as HCl> AlCl 3 > FeCl CrCl NiCl 2 , MgCl . Water evaporation in flow field surface was found to causing precipitation salts. At lower RH, water content decreased salt deposits completely blocked some channels caused death Moreover,...

Abstract The vinyl addition type copolymer poly(butoxymethylene norbornene‐ co ‐biphenyl oxyhexamethyleneoxymethylene norbornene) (P(BN/BphN)) was synthesized by using bis‐(β‐ketonaphthylimino)nickel(II)/B(C 6 F 5 ) 3 catalytic system. P(BN/BphN) sulfonated to give (SP(BN/BphN)) with concentrated sulfuric acid (98%) as sulfonating agent in a component solvent. ion exchange capacity (IEC), degree of sulfonation (DS), water uptake, and methanol permeability the SP(BN/BphN)s were increased...

The authors report the degradation behavior of polymer-electrolyte membrane fuel cells tested under two types water-management schemes: solid plate (SP) that mange water via flow and dew point control reactant gases, transport (WTP) actively remove liquid through micro-porous bipolar plates. Comparative experiments were conducted. Cell performance was tracked by periodic diagnostic testing. After cell testing, residual mechanical strength electrode assemblies characterized. It found both...

Cationic contamination is a well-known phenomenon that causes performance degradation and decrease in lifetime polymer electrolyte based electrochemical systems. Calcium significant cationic impurity due to its prevalence. In this work, the role of calcium investigated in-situ by injecting into cathode single fuel cell (PEFC) through nebulizer as solution sulphate (CaSO 4 ) deionized (DI) water. Stability tests are conducted determine contaminant effects at different current densities with...

Through plane distribution of cationic contamination on polymer electrolyte fuel cell (PEFC) was investigated at a fixed concentration 5 ppm Ca 2+ in the air stream an operating cell. A special purpose MEA prepared using five layers membrane, and four Pt wires (electrodes) were inserted between membrane layers. electrodes used to monitor through potential due permeation hydrogen oxygen from anode cathode, respectively resistance across thickness. At beginning test, permeated cathode first...

To understand the role of gas diffusion layer (GDL) in cation contamination, three methods were used to soak PEFC MEA with a cationic solution, major difference being whether CCM was completely/partially exposed solution or separated by GDL and gasket. Significant performance drop observed CCMs which direct/partially contact Ca 2+ no significant change occurred where It seems that acts as barrier transport +2 into CCM, possibly due very highly hydrophobic nature GDL. When surfactant added...

To correlate the cationic contaminant uptake of membrane electrode assembly (MEA) with polymer electrolyte fuel cell (PEFC) performance, MEAs were contaminated by saturating in varying concentrations H2SO4 and Al2(SO4)3 solution to establish ex situ equilibrium cation uptake. The then assembled tested a single hardware determine performance as function contamination level. Smaller MEA coupons also saturated at same time full-size characterized occupation fraction acid site titration. It is...

The effect of trace amounts formic acid (HCOOH) on proton exchange membrane fuel cell (PEMFC) performance is reported. Experimental approaches including long term stability test, cyclic voltammetry (CV) scans and electrochemical impedance spectroscopy (EIS) were used to evaluate characterize the contamination. results show that HCOOH can cause degradation in significantly contaminate electrodes. Furthermore, fully recovery from contamination could not be achieved only by reverting pure...

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The effect of the in-situ injection cationic contaminants on polymer electrolyte fuel cell (PEFC) performance is investigated. Four foreign cations (Ba 2+ , Ca Al 3+ K + ) were chosen as in this study due to their prevalence and chemical structure (e.g. valence). It found that cells with Ba(ClO 4 2 Ca(ClO exhibited little voltage change during a current hold test, Al(ClO 3 KClO showed larger decreasing increasing resistance. After recovery tests by switching back DI water from cation...

Cationic impurities may get introduced into Polymer Electrolyte Fuel Cells (PEFC) from the ambient air (e.g. roadside contaminants) and corrosion of stack balance plant components. Recovery cationic is investigated by simulating contamination with equilibrium uptake membrane electrode assembly (MEA) in a salt solution. The cation ionomer was performed soaking MEA 0.9 mM CaSO 4 29.1 H 2 SO solution following Kienitz’s procedure (1). Three different methods were used to soak understand role...

The effect of through plane cation contamination on PEFC was investigated using a multilayered membrane cell. MEA, similar to Watanabe et al. (1, 2), prepared five layers Nafion® 211 (~1 mil=25.4 μm thickness) membrane, and four Pt wires (electrodes) were placed between the membranes (Figure 1). electrodes used monitor through-plane potential that results from permeation hydrogen oxygen anode cathode, respectively. 1.14 mM CaSO 4 solution injected into air stream nebulizer at rate 65 μL/min,...

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