Thermal decomposition course of Eu(CH 3COO) 3·4H 2O and the reactivity at the gas/solid interface thus established

Abstract

The thermal decomposition course of europium acetate tetrahydrate (Eu(CH 3COO) 3·4H 2O) was probed on heating up to 1000 °C in a dynamic atmosphere of air by thermogravimetry and differential thermal analysis. The solid- and gas-phase decomposition products were identified by X-ray diffractometry, ex- and in situ infrared spectroscopy and mass spectrometry. Results obtained showed the acetate to dehydrate stepwise at 145–283 °C, and then decompose stepwise to yield eventually cubic-Eu 2O 3 at ≥663 °C encompassing the formation of intermediate oxycarbonate (Eu 2O(CO 3) 2/Eu 2O 2(CO 3) solid products (at 347–466 °C)) and H 2O, (CH 3) 2CO and CO 2 as primary gaseous products. A considerable enhancement of the production of the primary gas phase products at 400–450 °C and the emergence of (CH 3) 2C CH 2, CH 4 and CO molecules in the gas phase are ascribed to reactions occurring at the gas/solid interface at the expense of some of the primary products. These interfacial activities impart application-worthy adsorptive and catalytic functions for the associated solid products.