Size of gold particles

From a structural point-of-view the bulk metallic state, that is, fee lattice (with varying densities of defects such as twins and stacking faults) is generally established in gold nanoparticles of about 10 nm diameter and upwards. However, such particles still display many unusual physical properties, primarily as the result of their small size. Shrinking the size of gold particles has an important effect it increases both the relative proportion of surface atoms and of atoms of even lower coordination number, such as edge atoms [49] and these atoms in turn are relatively mobile and reactive. 

Figure 18. FT-IR for CO adsorbed on Au/Ti02 having different sizes of gold particles [49].

The size of gold particles increases with the final temperature of pre-treatment,5,62,206,207 and more in air than in hydrogen, for the reasons... 

Effect of Conditions of Storage on Size of Gold Particles... 

The size of gold particles depends on the conditions used for thermal pretreatment (Section 4.7), but there are enormous discrepancies between the various activation procedures. These are most usually performed in air,... 

Gold supported on metal oxides and hydroxides is active for CO oxidation at temperatures below 0°C irrespective of the type of metal oxide support when gold is deposited as nanoparticles. Table 1 shows three groups of gold catalysts which are classified in terms of stability, activity, and requirement as the size of gold particles for activity. 

Sizes of gold particles correlated with addition of trisodium citrate... 

The small size of gold particles is a crucial parameter to obtain active catalysts, not only for CO oxidation [8-12] but for many other reactions [4, 5, 13, 14]. The methods of preparation that lead to such types of catalysts are... 

The purpose of the present paper is to clarify the role of structure of the interface between Au and Ti02 for the genesis of high catalytic activity. To do this, we have investigated the effect of preparation conditions for deposition-precipitation on the size of gold particles. A simple physical mixture of Au colloid and Ti02 powder was also prepared for comparison. 

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