Study of the Alkylation of Isobutane with<i>n</i>-Butene over WO₃/ZrO₂Strong Solid Acid. 1. Effect of the Preparation Method, WO₃Loading, and Calcination Temperature

Abstract

A series of strong solid acids composed of WO 3 /ZrO 2 were prepared. Their crystal structure, surface state, and acidity were determined by the methods of X-ray diffraction, thermal gravimetric and differential thermal analysis, temperature-programmed reduction, laser Raman, and acidity measurement. The results revealed that ZrO 2 in WO 3 /ZrO 2 existed mainly in the tetragonal phase, the addition of WO 3 plays an important role in stabilizing the tetragonal phase of ZrO 2, and all of the samples possessed large surface areas. WO 3 in WO 3 /ZrO 2 is mainly monolayer dispersed, and a small amount crystallized on the ZrO 2 surface and partly reacted with ZrO 2 to form the bond of Zr−O−W, acting as the strong solid acid center. The catalytic properties of WO 3 /ZrO 2 strong solid acids for alkylation of isobutane with butene at different conditions were investigated. They had a better reaction performance than other strong solid acids; a parallel relationship could be drawn between the catalytic activity and the acid amounts as well as the acidic strength of the catalysts.