钌粉高纯化及颗粒形貌尺寸结构调控机理

The applications of ruthenium (Ru) as electrode and recording materials are rapidly expanding. The high-tech fields of industry have a strong demand for high performance Ru powder. However, the high quality requirement of Ru powders (high-purity, controllable morphology, size and structure) severely limited its applications. Based on our previous study on the synthesis of high-purity micro-spherical Ru particles, experimental research (including chemical separation, spray drying and microwave ignition) combined with theoretical study (such as finite-element simulations, thermodynamics and kinetics) will be used in this project. Key scientific issues, such as "the mechanisms of (NH4)2RuCl6 solution atomization, nucleation and particles growth in the thermal-air flow coupling field" and "the mechanisms of (NH4)2RuCl6 thermal decomposition and the evolution of particles microstructure in the microwave field", will be studied and solved. The experimental laws of impurities in both Ru element and Ru compounds during the chemical separation process will be analyzed. The mathematical model of (NH4)2RuCl6 solution evolution in thermal-air flow coupling field will be established. Both the growth pattern and evolution of (NH4)2RuCl6 particles in the spray drying process will be elaborated. The morphology, size and structure evolution of (NH4)2RuCl6 particles in the microwave field will be revealed. The influencing mechanisms of high-purity Ru with controllable morphology, size and structure on the comprehensive performance of Ru target will be revealed. Implementation of this project will help to enrich the basic theories of chemical separation, spray drying and microwave calcination processes, promote the development of high performance powders and high-purity materials synthesis theory and application of technology.

钌（Ru）以溅射薄膜的形式在电极材料和记忆存储材料中有重要应用，本项目面向高新技术对高性能Ru粉的需求，在本团队前期钌粉制备研究基础上，选取化学分离、喷雾干燥和微波煅烧为实验研究手段，采用有限元模拟、热力学和动力学为理论研究方法，实验结合理论解决“热-气流场耦合作用下氯钌酸铵[(NH4)2RuCl6]溶液雾化、溶质析出结晶和颗粒形核生长等机制”和“微波场中(NH4)2RuCl6颗粒显微结构演变规律及热解原理”等关键科学问题，归纳化学分离过程中Ru及其化合物中痕量杂质元素含量变化的分离作用规律，建立(NH4)2RuCl6溶液在热-气流耦合场中的演化数学模型，揭示喷雾干燥和微波煅烧过程中的影响因素及其作用规律，阐述高纯Ru粉形貌尺寸结构对Ru靶综合性能的影响机制。本项目的实施可丰富化学分离、喷雾干燥和微波煅烧等相关理论，推动高性能粉体及高纯材料制备的理论和技术发展。

钌（Ru）以溅射薄膜的形式在电极材料和记忆存储材料中有重要应用，本项目面向高新技术对高性能Ru粉的需求，选取了化学分离、喷雾干燥和微波煅烧为实验研究手段，采用热力学和动力学为理论研究方法，实验结合理论探讨了有关科学问题。通过XRD、TG-DSC、SEM、TEM、GDMS、ICP-MS以及粒径分析等现代分析测试技术对实验过程及样品进行全面跟踪与分析。探讨了“热-气流场耦合作用下氯钌酸铵[(NH4)2RuCl6]溶液雾化、溶质析出结晶和颗粒形核生长等机制”，结果表明：利用气雾化干燥可制备球形、微米级(NH4)2RuCl6颗粒，选取气液比为5 nL/ml、雾化温度为210℃、浓度为0.1mol/l时可制备出分散性良好、球形、微米级的(NH4)2RuCl6颗粒。讨论了“微波场中(NH4)2RuCl6颗粒显微结构演变规律及热解原理”，结果表明：(NH4)2RuCl6分解分为两段，255.0 ～314.0℃为第一段分解，产物为NH3、HCl和(NH3)4Ru3Cl12，314.0 ～360.9℃为第二段分解，产物为N2、HCl和 Ru单质。煅烧还原过程中，制备的Ru颗粒的形貌、粒径与升温速率有关，升温速率越大粉末破碎越少，升温速率大于10℃/min时破碎现象消失粉末为球形，且升温速率与粉末粒径大小成正比，与粉末比表面积成反比；研究了煅烧温度对Ru粉的影响，调节微米级球形Ru粉末的内部结构，较高的煅烧温度（> 750℃）有利于Ru颗粒的生长和附聚，而多孔Ru颗粒可通过在低温（<550℃）煅烧。将低BET（0.1963m2/g）的高纯Ru粉末制备成实验型高纯Ru靶，其密度12.24g/cm3，相对密度为99.2%，维氏硬度为481±10Hv。本项目的实施丰富了化学分离、喷雾干燥和微波煅烧等相关理论，推动了高性能粉体及高纯材料制备的理论和技术发展。