Mechanism of formation of nanosized copper particles in a nanoreactor based on the [LiAl2(OH)6]2[Cuedta]·nH2O supramolecular system

Abstract

The formation of nanosized copper particles in a nanoreactor based on the [LiAl2(OH)6]2[Cuedta]·nH2O supramolecular system [Li-Al-Cu(edta)] was studied by the DTA, XRPA, FMR, IR, and mass spectrometry methods. Thermal decomposition of Li-Al-Cu(edta) below 200°C occurs as two-stage removal of the interlayer water molecules. Above 200°C dehydration of [LiAl2(OH)6]+ metal hydroxide layers occurs simultaneously with destruction of [Cuedta]2− complexonate ions. The first stage of destruction (below 250–260°C) is a redox process that forms metallic copper and liberates gaseous carbon oxide and dioxide. At higher thermolysis temperatures, other gaseous products evolve (ammonia, hydrogen). The copper phase appeared during thermal decomposition as 20–50 nm isometric particles on the surface, while lenslike copper nanoparticles formed in the bulk substance.