Gold Nanoparticle-based Catalysts

Density Functional Theory (DFT) has shown that low-coordinated sites on the gold nanoparticles can adsorb small inorganic molecules such as O2 and CO, and the presence of these sites is the key factor for the catal5dic properties of supported gold nanoclusters. Other contributions, induced by the presence of the support, can provide parallel channels for the reaction and modulate the final efficiency of Au-based catalysts. Also these calculations extended for the adsorption of O and CO on flat and... 

The formation of PO over Au-based catalysts is a structure-sensitive reaction. Only hemispherical Au particles with a suitable size (2-5 nm) will selectively produce PO [167,168,403] and 2.2 to 2.4 nm particle size seemed to be optimum in the early experiments [31]. The most effective type of Au nanoparticles is prepared by the DP technique, which brings them in strong contact with the support. Gold particles smaller than 2 nm show a shift in selectivity from PO to propane [7,169-171,403]. This switch of epoxidation to hydrogenation for particles under 2 nm size indicates that small Au clusters exhibit different behaviour in surface properties from that of metallic Au [171] (see Fig. 6.17). 

K. Layek, R. Chakravarti, M. Lakshmi Kantam, H. Maheswaran, A. Vinu, Green Chem. 2011,13,2878-2887. Nanocrystalline magnesium oxide stabilized gold nanoparticles an advanced nanotechnology based recyclable heterogeneous catalyst platform for the one-pot synthesis of propargylamines. 

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