with Pt ou Au, you have to have a dispersion as high as possible. You need to minimise the metal loading (

Thank you very much for your answer. Impregnation seems to be also easier to apply. After impregnation, I will not calcinate the sample because I need it in liquid form. My question still remain, after obtaining the catalyst in a fluid form, how can I deposit it on the inner walls of a glass tube? And the calcination or drying comes after.

you can deposit directly your active phase (Pt) on substrate (glass tube or inner wall, monolith...). You can use dip-coating method. Pt precursor in liquid form, then, dip-coating with your substrate before calcination

BR,

Thank you Dr. Nguyen. I don't know if dip coating is possible, I will read more to see, I was thinking of spray coating inside the tube. I hope it will stick well on the inner wall after calcination. Do you think that calcination by 400 C is enough? Due to the glass, I can't go higher than 500 grad because it will start to melt. Best Regards.

Yes, 400-450°C is ok. by the way, you can also use spray coating. I haven't use spray coating before because I have a doubt about the reproducibility of this method.

BR,

Thank you very much for your sustainment. This gave me confidence that I found a good method. Many greetings.