Self-assembled Nafion films of varying thickness were generated on SiO2 terminated silicon wafer by immersion in dispersions different concentrations. The impact solvent/dispersion media was probed preparing from two types dispersions—IPA-diluted dispersion and Nafion-in-water dispersion. ascertained three techniques: variable angle spectroscopic ellipsometry (VASE), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS). techniques yielded consistent nominal thicknesses 4,...

We unravel the fate of hexafluoroacetone (HFA), a PFAS degradation product, on ice by combining surface science and DFT. Temperature-programmed desorption (TPD) X-ray photoelectron spectroscopy (XPS) experimentally show that HFA diffuses into film readily completely reacts to form diol (1,1,1,3,3,3-hexafluoropropane-2,2-diol). Desorption energies were measured for from underlying substrate (Pt(111)) as 44, 52, 62 kJ/mol, respectively. Calculations formation is favorable at least 29 kJ/mol....

Ultrathin crystalline silica layers grown on a Mo(112) substrate have been shown to be useful model oxide support in surface science catalyst studies. As the material plays an important role catalytic process, multitechnique study is presented characterize morphological and electronic properties of heteroepitaxial system ${\mathrm{SiO}}_{2}/\mathrm{Mo}(112).$ The long-range order epilayer which grows commensurate with $c(2\ifmmode\times\else\texttimes\fi{}2)$ unit mesh studied by low-energy...

A model system of alumina-supported vanadia particles, representing catalysts the type oxide1/oxide2, was prepared under ultrahigh vacuum (UHV) conditions and characterized regarding its structural electronic properties. As supporting oxide we used a thin, well-ordered alumina film grown on NiAl(110), which allows application scanning tunneling microscopy (STM), infrared reflection−absorption spectroscopy (IRAS), X-ray photoelectron (XPS) without charging effects. Vanadium particles were via...

A specialized genetic algorithm (GA) is used to search the structural space of samarium-doped ceria (SDC) for most energetically stable configurations which will predominate in low temperature fuel cells. systematic investigation all 3.2% SDC and a GA 6.6% are presented first time at DFT+U level theory. It was found that Sm atoms prefer occupy nearest neighbor (NN) position relative oxygen vacancy 3.2%, while 6.6%, balance exists between various Sm-vacancy interactions vacancies be separated...

The α-alkylation of acetophenone with benzyl alcohol through borrowing hydrogen has been studied using nickel catalysis.

To valorize lignin as a renewable source of aromatics, it is necessary to develop selective heterogeneous catalysts for the hydrodeoxygenation reaction aromatic oxygenates such anisole. Most metal-supported tested so far exhibit high conversion but low selectivity toward valuable hydrocarbons, yielding mainly phenolic compounds. gain insights into that catalytic system, we performed surface science experiments (X-ray photoelectron spectroscopy and temperature-programmed desorption) under...

Thermally induced changes in surface wettability, dewetting behavior, and proton transport of "self-assembled" nanothin Nafion® films (4–300 nm) on SiO2 substrate is reported. Thermal annealing induces switching the wettability 55 nm thinner from hydrophilic to super-hydrophobic. Thickness dependence this behavior observed with higher temperature required for lower thickness films, indicating highly restrictive mobility ionomer as film decreases. Dewetting only 4-nm thin film. Significant...

Surface supported, low dimensional gold nanostructures are of interest for plasmonic applications. Low readily accessible by solution-phase growth, where shape control through the addition growth-directing surfactants is well established. Yet, in chemical vapor deposition (CVD) has not been explored, and metallic films typically limited to nanoparticulate or thin film morphologies. This article describes self-seeded growth high aspect ratio plates wires CVD. A directed mechanism proposed,...

The air–water interface is believed to carry a negative electrostatic potential that nontrivial invert through pH, electrolyte, or electrolyte strength. Here, combined experimental and theoretical study, we show the close approach of negatively charged nanoparticle induces charge redistribution interface. Using different electrolytes control interfacial nanoparticles, X-ray photoelectron spectroscopy (XPS) results establish nanoparticles with more zeta adsorb closer than do same particles...

The open trough-and-row Mo(112) surface serves as substrate for the epitaxial growth of ${\mathrm{MoO}}_{2}.$ In early stage oxygen exposure, chemisorption induces a $p(2\ifmmode\times\else\texttimes\fi{}3)$ reconstruction missing row type on Mo(112). structure this reconstructed has been studied in detail by low-energy electron diffraction and scanning tunneling microscope. experimental findings can be explained based effective medium theory adsorption transition-metal surfaces, providing...

Nickel oxide yttria‐stabilized zirconia (NiO–YSZ) anode materials were synthesized via hydrolysis of the corresponding chloride solutions with NH 3 , +NaOH, and NaOH as precipitation agents. Powder properties such crystallite size, morphology, sintering behavior final NiO–YSZ also studied. The mechanism formation was established for different co‐precipitation techniques by direct observation Ni(NH ) n +2 complexes, Ni(OH) 2 NiO at stages synthesis process. A relationship between agent, order...

Alumina-supported vanadium particles were prepared under ultrahigh vacuum (UHV) conditions and characterized with respect to their structural CO adsorption properties. As supporting oxide, we used a thin, well-ordered alumina film grown on NiAl(110). This allows the application of scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRAS), X-ray photoelectron (XPS) without charging effects. Vanadium evaporation UHV leads growth nanometer-sized which strongly...

Single-cell solid oxide fuel cell (SOFC) experiments using Ni yttria-stabilized zironia (YSZ) and Co-YSZ anodes were performed to examine the electrochemical oxidation of H2 H2S/H2 mixtures. The introduction 10%v/v H2S into stream resulted in that initially showed significant signs degradation. However, when all metal was changed metal-sulfide, performance enhanced under most tested conditions, suggesting metal-sulfides are viable anode materials for SOFC systems. Electrochemical...

Dissociative and molecular adsorption of tert-butyl iodide on Pt(111) has been studied by single-crystal calorimetry (SCAC), photoelectron spectroscopy (XPS), reflection/adsorption infrared (RAIRS), density functional theory (DFT) calculations. Up to a t-BuI total coverage 0.07 ML, adsorbs dissociatively at 100 K form t-Buad plus Iad, with an integral heat reaction 223 kJ/mol. At higher coverage, up 0.15 molecularly directly the Pt surface atoms average 91 first layer is saturated. Between...

X-ray based techniques have been adopted as a diagnostic tool for both ex-situ and in-situ material characterization in PEMFC. Possible damage of Nafion due to irradiation is concern especially thin films. To investigate the effect on ultra-thin film structure properties, supported 10 nm films were prepared SiO2/Si substrate with inter-digitated gold arrays (IDA) exposed radiation at three power sources: 300, 200 100 W 45 mins. Proton conductivity each was measured by electrochemical...

Formic acid can undergo dehydration or dehydrogenation with variable selectivity over a range of metal catalysts. The among these reactions depends on the reaction mechanism and conditions pertinent each surface. This work provides mechanistic insight into decomposition formic cobalt at high- low-temperature regimes. adsorption Co(0001) single crystal was studied in ultrahigh vacuum by X-ray photoelectron spectroscopy temperature-programmed desorption. Insight is provided using density...