Try functionalized Au nanoparticles with acidic functional groups to improve the surface adhesion with silica.

Dear Lutf Ullah thank you for asking this very interesting technical question. It is well established that the catalytic behaviors of gold and palladium are different, but it is difficult to explain the specific activity / inactivity in certain reactions. Often this is just a matter of trial and error. The catalyst Pd/SBA-15 has been previously reported to be effective in the catalytic CO oxidation. This has been described in the following useful reference:

Preparation and characterization of SBA-15 supported Pd catalyst for CO oxidation

Article Preparation and characterization of SBA-15 supported Pd cata...

Unfortunately this paper has not been posted as public full text on RG, but the Abstract is already quite informative.

Au/SBA-15 is also catalytically active in CO oxidation when it is combined with a co-catalyst such as CeO2 or Fe2O3. For more information about this please have a look at the following interesting papers:

Au/CeO2-SBA-15 catalysts for CO oxidation: Effect of ceria loading on physic-chemical properties and catalytic performances

Article Au/CeO2-SBA-15 catalysts for CO oxidation: Effect of ceria l...

CO oxidation at 20 °C over Au/SBA15 catalysts decorated by Fe 2O 3 nanoparticles

Article CO oxidation at 20 °C over Au/SBA15 catalysts decorated by F...

and

Modifications induced by pretreatments on Au/SBA-15 and their influence on the catalytic activity for low temperature CO oxidation

Article Modifications induced by pretreatments on Au/SBA-15 and thei...

The latter article is freely available as public full text on RG.

I also found an example where both the gold and the palladium catalyst are active in CO oxidation. However, these catalyst are based on a different mesoporous silica nano-structure (TUD-1):

Noble Metal Nanoparticles Incorporated Siliceous TUD-1 Mesoporous Nano-Catalyst for Low-Temperature Oxidation of Carbon Monoxide

This article has been published Open Access (see attached pdf file). I hope this helps. Good luck with your research and best wishes, Frank Edelmann

Check the bellow article for Au@SBA15 particles:

Article Sustainable Protocol for the Reduction of Nitroarenes by Het...