Thermal decomposition course of Eu(CH3COO)3· 4H2O and the reactivity at the gas/solid interface thus established

Abstract

The thermal decomposition course of europium acetate tetrahydrate (Eu(CH3COO)3·4H2O) 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-Eu2O3 at ≥663 °C encompassing the formation of intermediate oxycarbonate (Eu2O(CO3) 2/Eu2O2(CO3) solid products (at 347-466 °C)) and H2O, (CH3)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 (CH3)2CCH2, CH4 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. © 2011 Elsevier B.V. All rights reserved.