Hello.

keep in mind that a Lewis acid is a chemical species containing an empty orbital which is capable of accepting an electron pair to form a Lewis adduct. This means that, if no other differences are relevant (such as spatial factors or crystalline lattice organization), the strength of acidic Lewis sights resulting from metals in your zeolites should increase with the element's normal reduction potential. Be, anyway, very careful with this indication, as other factors may overcome it.

Cheers

Mário Silva Hello Dear,

Thanks for your answer.

Actually I want to synthesis ZSM-5 with pure Bronsted and Pure Lewis acid sites separately. Do you think, Is it possible to synthesis these two catalysts with same metal ( i.e. Al or any other) via incorporation in their framework during hydrothermal treatment. or Can I synthesis these catalysts by Impregnation/Ion-exchange with particular metal to create desired type of acidity. In literature I found Sn, Ti, Zr, Hf have been used for Lewis acid sites, which metal I can use to generate pure Bronsted acid site (without LAS)?

Hello again.

I'm sorry but that's a bit more advanced than what I'm able to help with. Hope someone with more insight can step in.

Cheers!

Mário Silva Thank you so much.