The adsorption and decomposition of ethylene glycol on Rh(100) have been studied with temperature-programmed reaction spectroscopy and reflection absorption infrared spectroscopy. Ethylene glycol adsorbs onto the surface via the hydroxyl groups. At 150 K, both hydroxyl bonds are broken, forming an ethylenedioxy intermediate. At high coverage, a portion of the ethylene glycol molecules dehydrogenate only one hydroxyl bond, forming a monodentate species. These intermediates decompose further, with complete dehydrogenation and simultaneous C--C bond breaking occurring at around 290 K. Hydrogen and carbon monoxide are formed, which desorb at 290 and 500 K, respectively.

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In the study described in this paper we deposited gold, silver and copper on c-Al 2 O 3 as nanoparticles (<4 nm) and investigated the behavior of these nanoparticles in the preferential oxidation of CO in presence of H 2 . In addition, the effect of addition of CeO x and/or Li 2 O was investigated. All the three metals show preferential oxidation of CO at low temperatures. The oxides added to Au/c-Al 2 O 3 , Ag/c-Al 2 O 3 and Cu/c-Al 2 O 3 improve the catalytic performance of the gold, silver and copper. Interesting and synergistic effects were observed when both the CeO x and Li 2 O were added. Possible mechanisms are proposed.

Lateral adsorbate-adsorbate interactions result in variation of the desorption rate constants with coverage. This effect can be studied in great detail from the shape of a multi-isotherm. To produce the multi-isotherm, the temperature is increased in a (semi)stepwise fashion to some temperature, followed by maintaining this temperature for a prolonged time. Then, the temperature is stepped to a higher value and held constant at this new temperature. This cycle is continued until all of the adsorbates have desorbed. Using a detailed kinetic Monte Carlo model and an optimization algorithm based on Evolutionary Strategy, we are able to reproduce the shape of the experimentally measured multi-isotherm of nitrogen on Rh(111) and obtain the lateral interactions between the nitrogen atoms.

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