Production of a monolithic fuel cell stack with high power density.

The transportation sector is undergoing a technology shift from internal combustion engines to electric motors powered by secondary Li-based batteries. However, the limited range and long charging times of Li-ion batteries still hinder widespread adoption. This aspect is particularly true in the case of heavy freight and long-range transportation, where solid oxide fuel cells (SOFCs) offer an attractive alternative as they can provide high-efficiency and flexible fuel choices.

The Raman spectrum of isolated water clusters.

Cold water oligomers (H2O)n and (D2O)n with n = 2-5 are assigned in spontaneous Raman scattering spectra of seeded rare gas expansions for the first time. Comparison with infrared spectra provides direct experimental insights into the hydrogen bond-mediated excitonic OH oscillator coupling, which is responsible for ultrafast energy transfer between water molecules, usually suppressed by isotopic dilution in femtosecond experiments for the condensed phase. The experimental coupling constants are compared to those in state-of-the-art full-dimensional water potential energy hypersurfaces, leaving room for improvement in the description of the coupled dynamics in water.

Photoionization of small sodium-doped acetic acid clusters.

The uptake of sodium and the fragmentation before and after "soft" photoionization with ultraviolet light are investigated for small acetic acid clusters. The acetic acid clusters are generated in a supersonic expansion and ionized with ultraviolet light after doping with sodium in a pick-up chamber. The composition of the bare acetic acid clusters in the molecular beam is determined independently from complementary photoionization experiments using extreme ultraviolet light.

PFI-ZEKE photoelectron spectrum of CH2F2, ionisation potential and ionic fragmentation appearance potentials.

The first vibrationally resolved pulsed-field-ionisation zero-kinetic-energy (PFI-ZEKE) photoelectron spectrum of difluoromethane from its adiabatic ionisation potential (formation of the C(2v) conformer of CH(2)F(2)(+)) to the onset of the first ionic fragmentation channel is presented. Precise values for the adiabatic ionisation potential (12.7252 +/- 0.

The stiffness of a fully stretched polyethylene chain: A Raman jet spectroscopy extrapolation.

Linear alkanes with n=5-16 C-atoms are partially relaxed into their stretched all-trans conformation by supersonic jet expansion. Their longitudinal acoustic modes are identified by spontaneous Raman scattering and deperturbed from transverse bending mode components and Fermi resonance with combination states of the same symmetry. Comparison with quantum chemical predictions of the longitudinal modes in hydrocarbon chains with up to 54 C-atoms allows for a reliable extrapolation to the limiting product nnu(n)=2310+/-30 cm(-1) for large n, from which the elastic modulus of an ideal polyethylene chain in vacuum may be estimated at 309+/-8 GPa.

Infrared spectra of C2H6, C2H4, C2H2, and CO2 aerosols potentially formed in Titan's atmosphere.

Pure and mixed aerosols of ethane, ethylene, acetylene and carbon dioxide were generated in a collisional cooling cell and characterized by Fourier transform infrared spectroscopy between 600 and 4000 cm(-1). Pure ethane, pure ethylene, and mixed ethane/ethylene initially form supercooled liquid droplets, which over time crystallize to their stable solid phases. These droplets are found to be long-lived (up to hours) for pure ethane and mixed ethane/ethylene, but short-lived (up to seconds) for pure ethylene.

Adiabatic ionization potential of acetic acid and torsional dynamics of its cation.

Pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy and supersonic cooling are used to investigate the CH(3) torsional dynamics of the acetic acid cation and to determine an accurate value for the first adiabatic ionization potential of acetic acid (IP=85 912+/-5 cm(-1)), which has been the subject of debates for more than 40 yr. A doubling of the torsional barrier upon ionization is due to a significant shortening of the C-C bond and reduces the tunneling efficiency by an order of magnitude.

Raman spectroscopic evidence for the most stable water/ethanol dimer and for the negative mixing energy in cold water/ethanol trimers.

Spontaneous Raman scattering in supersonic jet expansions is used to prove that the mixed dimer of ethanol and water (corresponding to a volume fraction of 79% ethanol in the liquid) prefers ethanol in a gauche conformation as the hydrogen bond acceptor. This represents a particularly simple case of adaptive aggregation. Furthermore, it is shown experimentally that the isolated cold trimer built from one ethanol and two waters (corresponding to 64% ethanol in the liquid) has a significantly negative excess enthalpy, in line with the thermodynamic bulk observation at room temperature.

N-H...pi interactions in pyrroles: systematic trends from the vibrational spectroscopy of clusters.

Pyrrole and some of its methylated derivatives are aggregated in a controlled way in pulsed supersonic jet expansions. The cluster N-H stretching dynamics is studied using FTIR and Raman spectroscopy. Dimers, trimers and tetramers can be differentiated.

A peptide co-solvent under scrutiny: self-aggregation of 2,2,2-trifluoroethanol.

Trifluoroethanol (TFE) and its aggregates are studied via supersonic jet FTIR and Raman spectroscopy as well as by quantum chemistry and simple force field approaches. A multi-slit nozzle is introduced to study collisionally excited clusters. Efforts are made to extract harmonic frequencies from experiment for better comparison to theory.

Structural preferences, argon nanocoating, and dimerization of n-alkanols as revealed by OH stretching spectroscopy in supersonic jets.

n-Alkanols can occur in a multitude of energetically competitive conformational states. Using the OH stretching vibration as an infrared and Raman spectroscopic sensor in supersonic jet expansions, the torsional preferences around the Calpha-O and Cbeta-Calpha bonds are probed for n-propanol through n-hexanol. Raman detection is more powerful for isolated monomers, whereas IR spectroscopy is more sensitive for molecular complexes.

Hydrogen-bonded OH stretching modes of methanol clusters: a combined IR and Raman isotopomer study.

A comprehensive study of the OH and OD stretching fundamentals in clusters of methanol and its isotopomers CH(3)OD, CD(3)OH, and CD(3)OD provides detailed insights into the hydrogen-bond mediated coupling as a function of cluster size. The combination of infrared and Raman supersonic jet spectroscopy enables the observation and assignment of all hydrogen-bonded OH stretching modes of isolated methanol trimer and methanol tetramer. A consistent explanation for the spectral complexity observed more than a decade ago in methanol trimer in terms of low-frequency methyl umbrella motions is provided.

Concerted proton motion in hydrogen-bonded trimers: a spontaneous Raman scattering perspective.

Raman active symmetric O-H stretching modes are detected and assigned for the first time in isolated methanol, ethanol and methyl lactate trimers, providing insights into cluster structure, vibrational assignments and hydrogen-bond mediated couplings.