A Novel Approach to Prepare Well-Defined Silica-Supported Polyoxometalate Species by Reaction with a Chlorinated Support

Abstract EN

Polyoxometalates were grafted covalently on SBA-15 by a two-step procedure.

The dehydroxylated mesoporous silica was first modified by reaction with methyltrichlorosilane in presence of triethylamine.

The resulting solid was fully characterized and contained a mixture of mono- and digrafted species (≡Si–O)nSiMeCl3-n.

These surface Si–Cl bonds can react with lacunary polyoxometalates as in solution, yielding to a ≡Si–O–POM linkage.

However, solid state MAS NMR shows that only the digrafted species react with the polyoxometalate.

This new grafting method opens the way to the synthesis of a new class of catalysts which could operate in solution without leaching.