Reverse micelle-mediated synthesis of zirconia with enhanced surface area using alcothermal treatment

Abstract

High surface area zirconia with specific surface areas up to 593 m² g⁻¹ was prepared by hydrolysis of zirconium butylate in reverse micelles followed by a solvothermal (ethanol) treatment under mild conditions. In transmission electron micrographs and XRD powder patterns the material appears as an amorphous agglomerate consisting of small (<2 nm) primary particles that are at the beginning of crystallization. The observed type II nitrogen physisorption isotherms at 77 K are characteristic for non-porous powders. After the solvothermal treatment only small amounts of residual water (<5%) and surfactant (2.5% C) are detected. The micelle-mediated sol–gel process is shown to be a convenient route to high surface area zirconia without making use of supercritical drying and establishes a way to control the morphology and crystallinity by changing the duration of the solvothermal treatment and R_W.