CO preferential oxidation in microchannels over dendrimer-encapsulated Au supported on TiO2

N. DIVINS; J. LLORCA; C. MORENO; E. LÓPEZ; D. VEGA; A. RODRIGUEZ; F. GONZALEZ DE RIVERA; I. ANGURELL; M. SECO; O. ROSELL

Munich

Congreso; 15 International Congress on Catalysis; 2012

When gold nanoparticles of about 2-5 nm are deposited on metal oxides, such as TiO2, they exhibit exceptionally high activity to preferentially oxidize CO (CO-PrOx) in H2-rich environments. Numerous approaches have been described to prepare and stabilize such small nanoparticles on metal oxide supports. In this work, we have used pre-formed Au nanoparticles encapsulated in a Si-rich dendrimer shell. This method produces size-controlled Au nanoparticles whose particle size is established before deposition and, in addition, the dendrimer shell controls the interparticle distance, thus preventing their aggregation. These Au nanoparticles are stable at elevated temperature, as deduced from AFM, XPS and SEM studies and, consequently, they have been used for CO-PrOx at T>400 K. As a final point, the nanoparticles have been supported over TiO2-tailored microchannels of a silicon micromonolith to test them under CO-PrOx reaction conditions.