FORMATION AND STRUCTURE OF TITANIUM ETHYL PHOSPHATES

Abstract

Titanium ethyl phosphates (TiEP) synthesized by the reaction of Ti(SO₄)₂ with a mixture of mono- C₂H₅OPO₃H₂ and diethyl phosphates (C₂H₅O)₂PO₂H (EP) in aqueous media were characterized by various means. XRD pattern of TiEP featured a strong diffraction peak at 2θ=6.8°. When TiEP was treated at 900°C in air, the material crystallized as TiP₂O₇, implying the molar ratio P/Ti of TiEP to be 2.0. This indicates that only monoethyl phosphate ions reacted with Ti⁴⁺ ions. The chemical formula of TiEP could be shown as (C₂HSOPO₃)₂Ti·1.7H₂O. These facts suggested that TiEP is composed of a multilayer alternating bimolecular layer of ethyl phosphates and hydrated titanium phosphate phase. Ethyl groups and H₂O molecules in the layers were removed by outgassing at 200°C to give the materials having mesopores with a diameter of ca. 2.6nm