SYNTHESIS OF α-ZIRCONIUM PHOSPHATE FROM ACETYL ACETONATE SOLUTION; A COMPARATIVE SYNTHESIS STUDY OF α-ZrP

Abstract

Three main routes of synthesis; namely the reflux, the direct precipitation, and the sol-gel methods, are used to prepare α-zirconium phosphate α-Zr(HPO 4 ) 2 .2H 2 O or simply α-ZrP. Within each separate method of synthesis, different starting precursors and/or reaction conditions are tested for optimization to obtain the crystalline product. Different products were characterized using TGA-DTA data, SEM photos, N 2 -gas absorption-desorption measurements, and FT-IR absorption spectra. The products showed different extents of crystallinitiy as roughly or qualitatively shown by their XRD patterns. The results are explained on the basis of each synthesis route and reaction conditions. In contrast to the familiar results that the initial un-refluxed product of rapid precipitation is basically amorphous ZrP, a careful washing strategy confirmed that this is a crystalline ZrP contaminated with a minority of solid H with a 1:1 mixture of mono-and diethyl phosphates were amorphous. Chemical analysis shows a reasonable agreement between the experimental ratios of P/Zr and the calculated values. Compared to other methods of synthesis, the direct precipitation seems to be more efficient in obtaining a product of good yield and improved crystallinity.

Synthesis and Characterization of Expanded Layer-Spacing Zirconium Phosphate by Ion-Exchange and Intercalation Processes

“…This may be due to a slower decomposition of the zirconium precursor (zirconium acetylacetonate complex) during reaction with phosphate anion to form crystalline product. However, its degree of crystallinity is not as much good as that obtained by decomposition of zirconium-flouro complexes as reported before [1].…”

“…This was ascribed to the gradual decomposition of the zirconium complexes that enabled a slow precipitation of zirconium phosphate to produce very large and well-formed crystals [1,10].…”

“…The possible routes of synthesis of crystalline zirconium phosphate were tried as described before [1] where the best results have been obtained by decomposition of zirconium complexes. This was ascribed to the gradual decomposition of the zirconium complexes that enabled a slow precipitation of zirconium phosphate to produce very large and well-formed crystals [1,10].…”

“…The prepared samples were identified through their interlayer distance by XRD Powder pattern at conditions described earlier [1].…”

“…-ZrP samples were prepared by sol-gel method as previously described 1 . By adding acetylacetone to zirconium isopropoxide, Zr(OPr iso ) 4 under nitrogen atmosphere, a complex is formed.…”