How to prepare zirconium chloride?

Zirconium(IV) chloride, also known as zirconium tetrachloride, (ZrCl4) is an inorganic compound frequently used as a precursor to other compounds of zirconium. This white high-melting solid hydrolyzes rapidly in humid air.

Unlike molecular TiCl4, solid ZrCl4 adopts a polymeric structure wherein each Zr is octahedrally coordinated. This difference in structures is responsible for the disparity in their properties: TiCl4 is distillable, but ZrCl4 is a solid. In the solid state, ZrCl4 adopts a tape-like linear polymeric structure—the same structure adopted by HfCl4. This polymer degrades readily upon treatment with Lewis bases, which cleave the Zr-Cl-Zr linkages.

This conversion entails treatment of the oxide with carbon as the oxide "getter" and chlorine.

ZrO2 + 2 C + 2 Cl2 → ZrCl4 + 2 CO

A laboratory scale process uses carbon tetrachloride in place of carbon and chlorine:

ZrO2 + 2 CCl4 → ZrCl4 + 2 COCl2