Abstract
Zirconium containing MCM-41-type has been synthesized by a near neutral route. Various solids, with Si/Zr molar ratios ranging from 20 to ∞, were prepared. All these solids have high surface area and good crystallinity. Addition of zirconium results in a linear increase of both the Lewis and Brönsted acidities. At least one-third of zirconium is at the surface or near the surface, probably in the form of [(≡Si–O)
3Zr–O
−] species. As a consequence, introduction of zirconium on the surface results in the appearance of a negative charge, compensated by sodium ions which can be exchanged.