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Surface chemistry of catalysis by gold

“…Nieuwenhuys' group observed that while preoxidized samples of Au/TiO2 were initially inactive, their activity increased following exposure to CO and O2 (376). On the other hand, prereduced samples exhibited a high activity from the reaction onset.…”

Relation between nanoscale Au particle structure and activity for CO oxidation on supported gold catalysts

“…The explanations for the catalytic activity of small gold particles presented so far have mainly focused on the size of the Au particles [5,6,[15][16][17][18][19] and the nature of the support material [20][21][22], and include e.g. electronic quantum-size effects, strain, oxygen diffusion via the support, and the oxidation state of the gold particles [13,[23][24][25][26][27] A more fundamental approach to understand the catalytic activity of small gold particles is to determine how the properties of these particles differ from the inert bulk gold.…”

How Different Characterization Techniques Elucidate the Nature of the Gold Species in a Polycrystalline Au/TiO2 Catalyst

“…The latter is assigned to CO adsorbed at the rim sites between neutral Au 0 clusters (Au n 0 ) and TiO 2 [12,13]. The significant intensity between these signals turns out to result from an additional species (positively charged metal clusters, Au n + [14]): after desorption of CO from Au n 0 at 155 K its signal is visible as a shoulder at the slightly shifted CO/Au 3+ band at 2158 cm -1 band (spectrum a 500 '). Only relation to the XAFS results shows, however, that the sample has been changed by the treatment, because there was no Au 0 in the initial state.…”