Zirconium-Substituted Isopolytungstates: Structural Models for Zirconia-Supported Tungsten Catalysts

Hugo Carabineiro (1, 2) , Richard Villanneau (3) , Xavier Carrier (1) , Patrick Herson (3) , Francisco Lemos (2) , Fernando Ramôa Ribeiro (2) , Anna Proust (3) , Michel Che (1)

1 LRS - Laboratoire de Réactivité de Surface
2 Centro de Engenharia Biologica e Quimica
3 CIM2 - Laboratoire de Chimie Inorganique et Matériaux Moléculaires

The synthesis and characterization of a series of mixed W-Zr polynuclear Lindqvist-type complexes, deriving from hexatungstate [W6O19]2-, are described in this work. This family of compounds is built from {W5O18Zr}2- moieties as shown by the X-ray structures of the monomeric [W5O18Zr(H2O)3-n(DMSO)n]2- (n ) 1 and 2) and dimeric [{W5O18Zr(í-OH)}2]6- anions. A comprehensive spectroscopic study (183W NMR, FTIR, Raman, EXAFS, and EPR) of these compounds is presented. The goal of incorporating ZrIV cations into an oxotungstic core is to obtain spectroscopic models that could mimic the interactions that develop in supported catalysts between the active phase and the supporting oxide. This work tends to show that these molecular compounds can be regarded as soluble structural analogues of WOx/ZrO2 catalysts, which are interesting candidates for the skeletal isomerization of light n-alkanes.

Mots clés: isopolyanion; polyoxometalate; spectroscopic model; tungsten; zirconium; XAS; tungstated zirconia

Domaines: Catalyse; Chimie inorganique

Hugo Carabineiro, Richard Villanneau, Xavier Carrier, Patrick Herson, Francisco Lemos, et al.. Zirconium-Substituted Isopolytungstates: Structural Models for Zirconia-Supported Tungsten Catalysts. Inorganic Chemistry, 2006, 45, pp.1915-1923. ⟨10.1021/ic051941l⟩. ⟨hal-00084005⟩