Processing and properties of high-purity micro-lamellate (NH4)2RuCl6 particles.

(NH₄)₂RuCl₆ is an important precursor in the synthesis of Ru powder with high-purity requirement. In this study, high-purity (>99.999 wt%) micro-sized (NH₄)₂RuCl₆ pieces were synthesized by distillation and precipitation from crude Ru powder. Then, the thermal decomposition behavior of the (NH₄)₂RuCl₆ pieces was investigated. The decomposition process included two stages. First, (NH₄)₂RuCl₆ was decomposed from 255.0°C to 314.0°C, with the endothermic peak located at 309.4°C. At this stage, HCl and NH₃ were released, while the dense micro-pieces were transformed to loosened micro-pieces due to the thermal decomposition. Then, the solid phase [(NH₃)₄Ru₃Cl₁₂] kept decomposing from 314.0°C to 352.7°C, HCl and N₂ were released, and agglomerated Ru particles were achieved. Thermogravimetric analysis-differential thermal analysis-mass spectrum coupling (TG-DTA-MS) was used to monitor the thermal decomposition process and identify the released gaseous phases, respectively. The solid phases in different stages were characterized by high-temperature X-ray diffraction (HTXRD). A good understanding of the processing and thermal decomposition of (NH₄)₂RuCl₆ is crucial in the creation of Ru products. [ABSTRACT FROM AUTHOR]