Study on thermal transformation of CuHPO4.H2O obtained by acetone-mediated synthesis at ambient temperature

Abstract

Copper hydrogenphosphate monohydrate, Cu- HPO4.H2O, was synthesized for the first time through simple and rapid method using the mixing of copper carbonate and phosphoric acid in acetone medium at ambient temperature. The obtained CuHPO4.H2O decomposed in three stages via dehydration and deprotonated hydrogenphosphate reactions, revealed by TG/DTG and DSC techniques. The kinetic triplet parameters (Ea, A, and n) and thermodynamic functions (δHz.ast;, δGz.ast;, and δS*) for the first two decomposed steps were calculated from DSC data. All the obtained functions indicate that the deprotonated HPO4 2- reaction for the second step occurs at a higher energy pathway than the dehydration reaction for the first step. The calculated wavenumbers based on DSC peaks were comparable with FTIR results, which support the breaking bonds of OH (H2O) and P-OH (HPO4 2-) according to decomposed mechanisms. All the calculated results are consistent and in good agreement with Cu- HPO4.H2O's thermal transformation mechanisms. © Akademiai Kiado, Budapest, Hungary 2012.