Active surface formation of tungstated zirconia catalysts for n-heptane isomerization

Abstract

A comprehensive study of the regularities in the formation of active surface of WO3/ZrO2 catalysts for n-heptane isomerization was performed. The WO3 content in the catalysts (10–35 wt. %) and calcination temperature of WO3/ZrO2 (700–1000 °C) were found to affect the textural characteristics, phase composition, acidic and catalytic properties in n-heptane isomerization. It was shown that the catalyst with high isomerization activity comprises three phases: tetragonal zirconia (45–70%), monoclinic zirconia (20–41%), and monoclinic tungsten oxide (10–14%). The indicated phase composition can be created by thermal treatment at 850–950 °C of WO3/ZrO2 containing 25 wt. % WO3.