CO Oxidation on Unsupported Dendrimer-Encapsulated Gold Nanoparticles

Abstract

Unsupported gold nanoparticles in solution are reported here for the first time to catalyze the oxidation of CO at ambient conditions. Gold was stabilized in solution by various polyamidoamine dendrimers. Dendrimer-encapsulated gold nanoparticles (DENs) 0.5−2.5 nm in diameter have low initial activity. With storage time, however, the activity of the aged DENs increased and became comparable to a reference Au−TiO2 catalyst with the same gold loading and average gold particle size, which was tested under the same reaction conditions. The activation is attributed to partial hydrolysis of gold as followed by UV−vis spectroscopy.