Nuclear magnetic resonance microimaging investigation of membrane electrode assembly of fuel cells: morphology and solvent dynamics

Resolve the pore structure and dynamics of Nafion 117: application of high resolution 7Li solid state nuclear magnetic resonance spectroscopy

“…A variety of nuclear spin probes including 19 F, [6][7][8][9][10][11] 129 Xe, 11 13 C, 12-15 1 H, 13 23 Na, 16,17 7 Li, 35 Cl, 18 31 P 19 have been employed to investigate the structure and dynamics of Nafion via high resolution one-dimensional liquid and solid state NMR spectra, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] two-dimensional 19 F- 13 C correlation and exchange, 10,14,15 self-diffusion and relaxation of 1 H, 20-24 2 D 24 and 19 F 25 etc. NMR micro-imaging has also been explored for studying PEM of fuel cells, 26,27 the operating fuel cell 28 or 3D imaging of fuel cells. 29,30 A large body of information has accumulated from these studies and many interesting properties of Nafion have been revealed.…”

Compound‐Specific Imaging of Methanol Fuel Cell for Performance and Degradation Studies Using a Mini Positron Emission Tomograph

“…[30][31][32] Furthermore different vibrational and fluorescence chemical imaging and electrochemical microscopy methods are also known in adsorption studies. [33][34] The positron emission tomography presented here, a well-known technique for biochemical functional imaging in human and animal bodies, is especially adaptable for profiling and monitoring of positron-emitter labeled compounds in chemically reactive surface area in few cm-scale. The main advantages of positron emission tomography are the high sensitivity and the high molecule specificity.…”

“…Several imaging methods are well known for characterization of different processes of physicochemical and electrochemical surface area such as X‐ray computed tomography for failure analysis of cell electrode, MRI and Neutron Imaging for water imaging in cell [30–32] . Furthermore different vibrational and fluorescence chemical imaging and electrochemical microscopy methods are also known in adsorption studies [33–34] . The positron emission tomography presented here, a well‐known technique for biochemical functional imaging in human and animal bodies, is especially adaptable for profiling and monitoring of positron‐emitter labeled compounds in chemically reactive surface area in few cm‐scale.…”

Multinuclear Solid State Nuclear Magnetic Resonance Investigation of Water Penetration in Proton Exchange Membrane Nafion-117 by Mechanical Spinning

“…More recently, high resolution 7 Li solid state NMR spectra unveil fine structures of nanopores and channels that are closely related to the proton conductivity of the material . Furthermore, high resolution NMR microimaging , with spatial resolution down to tens of micrometers has been carried out on this material, revealing a number of novel structural and dynamic properties of this material. Theoretical and computational investigations have aided our understanding of this material, including fluid dynamics simulation, − theoretical analysis based on equilibrium statistical mechanics, Monte Carlo simulation, molecular dynamics simulation, ,− ab initio quantum chemistry computation, , etc.…”