Undertake different runs with variation in the stoichiometric quantities of precursor of gold (gold salt like chloroauric acid hydrate), reductant, stabilizer and capping agent.

Article EFFECT OF SUPPORT ON ADSORPTION PROPERTIES OF GOLD NANOPARTI...

Try to use our approach. Unfortunately our article is in russian.

For the formation of nanoparticles, an aqueous solution of HAuCl4 with a metal concentration of 2.4 · 10-5 g / ml was applied to the support. As a support we used HOPG, allumina, titania and silica. Support with HAuCl4 was dried and calcined at T = 750-850K in vacuum. Mobility of gold clusters on the surface of support is high enough, so duration of calcination determines the average size of nanoparticles.

Thank you so much for the information.

In general the Turkevich method is used to prepare supported Au catalysts. As stated above concentrations of reactants are important. Typically the more dilute, then the smaller the size. Loadings of 1% metal would tend to be smaller than 5% metal. Take a look at these webinars where you'll find some references:

Metal colloids - their preparation, application and characterization

https://www.brainshark.com/malvern/vu?pi=529368070&b=1&tx=120486&c1=22

Silver colloids and invisible ink

https://www.brainshark.com/malvern/vu?pi=560497681&b=1&tx=120486&c1=22

I worked with a variety of supported metal catalysts including Au during my Ph.D. You'll probably see a lot of literature in this area by G C Bond (my Ph.D supervisor).