Structural analysis of tungsten–zirconium oxide catalyst by W K‐edge and L 1 ‐edge XAFS

The local structure of tungsten species in tungsten–zirconium–oxide catalysts (WO x ZrO 2 ) was first investigated by W K‐edge x‐ray absorption spectroscopic techniques. A proportion of WO 4 to the total WO x species was quantitatively analyzed with W L 1 ‐edge x‐ray absorption near edge structure (XANES). Tungsten species in 15 wt% WO x ZrO 2 , which is the most active for n ‐butane skeletal isomerization, consists of a mixture of WO 3 ZrO 2 solid solution, WO 6 aggregate and WO 4 species on the catalyst surface. The tungsten species does not possess long‐range ordering.