Some peculiarities of zirconium tungstate synthesis by thermal decomposition of hydrothermal precursors

• Synthesis of ZrW2O8 using hydrothermal method.
• On hydrothermal synthesis optimal conc. of HCl in the reaction mixture is 2.3 М.
• Thermal decomposition of ZrW2O7((OH)1.5,Cl0.5)·2H2O begins are 200 °С.
• Amorphous intermediate crystallizes into cubic single-phase ZrW2O8 above 550 °С.
• ZrW2O8 destructed at temperatures above 700 °С.

This article discusses some peculiarities of the synthesis of ZrW2O8 (1) using thermal decomposition of the precursor ZrW2O7((OH)1.5,Cl0.5)·2H2O (2) prepared by hydrothermal method. On hydrothermal synthesis of 2 the optimal concentration of hydrochloric acid in the reaction mixture is about 2.3 М. TG approach to determine the chemical composition of the precursor was suggested. It has been found that the precursor for the synthesis of zirconium tungstate has chemical formula 2. Thermal decomposition of the precursor 2 begins at 200 °С and affords an amorphous intermediate, which crystallizes as a cubic phase 1 above 550 °С with an exoeffect. The temperature of the beginning of the transition from amorphous to the crystalline state is 350 ± 25 °С.