Supported nanoparticles are one of the largest classes of heterogeneous catalysts and are used both in the petrochemical and the fine chemical industries. In these systems, there are numerous parameters influencing the catalyst performances, such as the size and the distribution of the metallic nanoparticles, but also their interaction with the support surface. Recent studies of Gajan et al. showed that it was possible to prepare small Au nanoparticles (AuNPs) of ca. 2nm supported on silica covered with Me3SiO- groups (passivated silica) instead of OH functionalities, which greatly modifies the hydrophobic character of the surface. While AuNPs supported on standard SiO2 (-OH covered) is active in the oxidation of CO with pure O2, Au NPs on passivated silica were active only when H2 was added in the feed1. In addition, when used for the epoxidation of stilbene by air in methylcyclohexane, the catalyst performances are dramatically increased by the presence of the passivating group (Me3SiO-) at the surface of silica, which was related to the hydrophobicity of the support.Here, we investigate the effect of the presence of passivating group at the surface of silica on the structure, the reactivity of metallic nanoparticles, as well as their selectivity in reactions where water is an important component, e.g. Water-Gas-Shift reaction.

Changing the interface of metal nanoparticles supported on silica: Effect on structure and reactivity

247th National Meeting (2014)

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