Gold, still a surprising catalyst in heterogeneous reactions

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A comparative study of the effect of addition of CeOx and Li2O on gamma -Al2O3 supported copper, silver and gold catalysts in the preferential oxidation of CO

In the study described in this paper we deposited gold, silver and copper on gamma -Al2O3 as nanoparticles

A comparative study of the effect of addition of CeOx and Li2O on gamma -Al2O3 supported copper, silver and gold catalysts in the preferential oxidation of CO

In the study described in this paper we deposited gold, silver and copper on gamma -Al2O3 as nanoparticles

A surface science approach to understand CO and NO chemistry on Au surfaces

Abstract only

Ethanol adsorption, decomposition and oxidation on Ir(111) : a high resolution XPS study

Ethanol (C2H5OH) adsorption, decomposition and oxidation is studied on Ir(111) using high-energy resolution, fast XPS and temperature-programmed desorption. During heating of an adsorbed ethanol layer a part of the C2H5OHad desorbs molecularly, and another part remains on the surface and decomposes around 200 K; these two decomposition pathways are identified, as via acetyl (H3CCO) and via COad+CH3ad, respectively. Acetyl and CH3ad decompose around 300 K into CHad (and COad). CHad decomposes forming Cx and H2 around 520 K. In the presence of Oad an acetate intermediate is formed around 180 K, as well as a small amount of CH3ad and COad. Acetate decomposes between 400-480 K into CO2, H2(/H2O) and CHad

Methanol decomposition and oxidation on Ir(111)

The adsorption, decompn., and oxidn. of methanol (CH3OH) has been studied on Ir(111) using temp.-programmed desorption and high-energy resoln. fast XPS. Mol. methanol desorption from a methanol-satd. surface at low temp. shows three desorption peaks, around 150 K (alpha ), around 170 K (beta 1), and around 220 K (beta 2), resp. The alpha peak is assigned to methanol adsorbed on top of the first, chemisorbed layer, whereas beta 1 and beta 2 are both assigned to methanol directly coordinated to the metal surface atoms (chemisorbed). The CH3OHad responsible for the beta 2 desorption peak appears as a sep. component in the C 1s core level spectra. A part of the initially adsorbed methanol decomps. into COad and Had around (or even below) 175 K. Intermediate CHxO species of CH3OH decompn. were not obsd. The formation of a small amt. of CHxad indicates that (Hx)C-O(H) bond scission occurs as well. Temp.-programmed desorption expts. confirm that CHxad species form, as evidenced by a high-temp. (500 K) H2 formation peak due to decompn. of CHad. The presence of Oad causes a downward shift in the C 1s and O 1s BEs of molecularly adsorbed methanol, but the desorption barrier for mol. methanol desorption is not significantly influenced by the presence of Oad. A stable reaction intermediate, most probably methoxy (CH3Oad), was obsd. in the presence of Oad, between 160 and 220 K. It is an intermediate in the formation of both formate (HCO2ad) and COad, which occurs around 220 K. Formate decomps. around 350 K into CO2 (g) and Had (which reacts with the remaining oxygen to H2O), whereas the COad reacts with Oad around 400 K. [on SciFinder (R)

Benzene adsorption and oxidation on Ir(111)

Adsorption, decompn. and oxidn. of benzene on Ir(1 1 1) was studied by high resoln. (synchrotron) XPS, temp. programmed desorption and LEED. Mol. adsorption of benzene on Ir(1 1 1) is obsd. between 170 K and 350 K. Above this temp. both desorption and decompn. of benzene take place. An ordered adsorbate structure was obsd. upon adsorption around 335 K. Decompn. involves C-C bond breaking as the formation of CHad is obsd. The presence of a satd. Oad layer (0.5 ML) weakens mol. benzene adsorption and suppresses decompn. [on SciFinder (R)