Hyllested Tennant (mariadate80)

We report the temperature influence of the OHad and Oad electroadsorption on RuO2(110) films grown on TiO2(110) crystals in alkaline media. From the temperature effect, we evaluate the enthalpy and entropy of the OHad and Oad electroadsorption, including the adsorbate-adsorbate interactions that we analyze using the interaction parameters of the Frumkin-isotherm model. We found that the adsorbates repel each other enthalpically but attract each other entropically. Our result suggests that an entropy analysis is necessary to capture the electroadsorption behavior on RuO2 since the enthalpy-entropy competition strongly influences the electroadsorption behavior. Our observation of an entropic force is consistent with the view that water may be a mediator for adsorbate-adsorbate interactions.Copper oxides species deposited on ceria rods, particles, and cubes were examined for low-temperature oxidation of CO. It was found that the shape of ceria altered the dispersion and chemical state of copper species considerably. CuOx monolayers and bilayers were formed on ceria rods and particles, while multilayers and faceted particles co-existed on ceria cubes. The formation of Cu+ species at the copper-ceria interface involved a significant charge transfer from copper oxides to the ceria surface via a strong electronic interaction, which was more pronounced on ceria rods. The concentrations of surface Cu+ and oxygen vacancies followed the order rods > particles > cubes, in line with their catalytic activity for CO oxidation at 343 K.The low-energy electronic states of UN and UN+ have been examined using high-level electronic structure calculations and two-color photoionization techniques. The experimental measurements provided an accurate ionization energy for UN (IE = 50 802 ± 5 cm-1). Spectra for UN+ yielded ro-vibrational constants and established that the ground state has the electronic angular momentum projection Ω = 4. Ab initio calculations were carried out using the spin-orbit state interacting approach with the complete active space second-order perturbation theory method. A series of correlation consistent basis sets were used in conjunction with small-core relativistic pseudopotentials on U to extrapolate to the complete basis set limits. The results for UN correctly obtained an Ω = 3.5 ground state and demonstrated a high density of configurationally related excited states with closely similar ro-vibrational constants. Similar results were obtained for UN+, with reduced complexity owing to the smaller number of outer-shell electrons. The calculated IE for UN was in excellent agreement with the measured value. Improved values for the dissociation energies of UN and UN+, as well as their heats of formation, were obtained using the Feller-Peterson-Dixon composite thermochemistry method, including corrections up through coupled cluster singles, doubles, triples and quadruples. An analysis of the ab initio results from the perspective of the ligand field theory shows that the patterns of electronic states for both UN and UN+ can be understood in terms of the underlying energy level structure of the atomic metal ion.The role of electronic predissociation (EP) in the dissociation dynamics of rare gas⋯dihalogen complexes (Rg⋯X2) prepared in the B electronic state was probed using ion time-of-flight velocity-map imaging. Specifically, EP of complexes prepared in the T-shaped Ar⋯I2, Ne⋯I2, He⋯I2, Ar⋯Br2, Ne⋯Br2, and He⋯Br2 levels with varying amounts of X2 vibrational excitation, ν', was investigated. The atomic I(2P3/2) or Br(2P3/2) EP fragments were probed using ion time-of-flight velocity-map imaging. Definitive evidence for EP was observed only for the Ar⋯I2 complex, and it occurs for all of the T-shaped intermolecular levels investigated, those with ν' = 12-22, 24, and 25. The relative yields for EP in these levels measured as a function of ν' are consistent with previously reported yields for the competing mechanism of vibr