Solvated metal atom dispersion

In both cases, the Au nanoparticles behave as molecular crystals in respect that they can be dissolved, precipitated, and redispersed in solvents without change in properties. The first method is based on a reduction process carried out in an inverse micelle system. The second synthetic route involves vaporization of a metal under vacuum and co-deposition of the atoms with the vapors of a solvent on the walls of a reactor cooled to liquid nitrogen temperature (77 K). Nucleation and growth of the nanoparticles take place during the warm-up stage. This procedure is known as the solvated metal atom dispersion (SMAD) method. 

Solvated Metal Atom Dispersed (SMAD) Bimetallic Catalysts... 

Solvated metal atom dispersion or impregnation (SMAD or SMAI)... 

SOLVATED METAL ATOM DISPERSION (SMAD) METHOD FOR THE PREPARATION OF NANOPARTICLES... 

Fig. 9.1. Apparatus used for the preparation of nanoparticles by the Solvated Metal Atom Dispersion Method (SMAD). (Reprinted with permission from Klabunde, K. J Acc. Chem. Res., 1975, Fig.1, copyright (1975) American Chemical Society.)...

Figure 5 shows high-resolution electron microscope images of several gold nanoparticles formed by this metal vapor synthesis method, often called Solvated Metal Atom Dispersion (SMAD). 

A more sophisticated technique, the so-called solvated metal atom dispersion technique, has been developed by Klabunde and Tanaka (70). It involves the evaporation of metal atoms in the presence of complexing solvents to yield solvated metal atoms. The solution is brought into contact with the support at low temperatures and the slurry obtained is warmed to room temperature. The excess solvent is removed by further... 

In solvated metal atom dispersion (SMAD) method solvated atoms prepared at very low-temperature are used as transient, highly reactive organometallic reagent for the deposition of Sn-Pt bimetallic particles onto different supports. In another approach chemical vapor deposition (CVD) using tin organometallic compounds was applied. For example, the selective reaction of Sn(CH3)4 vapour with Pt nanoparticles supported on Si02 appears to be very promising preparation method. 

Esoteric methods of forming supported metals or their analogues include the use of aerogels and xerogels/ ° photolithography and electron-beam lithography/ and a solvated metal-atom dispersion method/ ... 

In order to discriminate between the activity of the different gold species on ceria, our group prepared ceria-supported gold catalysts by classical deposition-precipitation (DP) followed by drying at 393 K, and by the solvated metal atom dispersion (SMAD) technique... 

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