论文部分内容阅读
采用Fact Sage软件,对NbC l5-H2-Ar体系化学气相合成纳米金属Nb粉的热力学进行研究并对热力学研究结果进行实验验证。结果表明:在标准大气压下,NbC l5(g)被氢气还原为Nb(s)是一个多步骤反应过程,其间产生大量中间产物(低价氯化物);该反应过程可控制在较低氢气比率(n(NbC l5):n(H2)<1:180)和较低温度(<1050°C)下完全进行;适量的惰性载流气体可同时提高NbC l5转化率和粉末收得率。根据热力学计算得到的合成条件为n(NbC l5):n(H2):n(Ar)=1:120:1以及950°C,实验成功制得平均粒径为30~50 nm且粒度分布均匀的纳米金属Nb粉,相应的NbCl5转化率达到96.1%,粉末收得率为85%。
The thermodynamics of NbC l5-H2-Ar system chemical vapor-phase synthesis of nano-metal Nb powder was investigated by Fact Sage software and the thermodynamic study results were verified by experiments. The results show that the reduction of NbCl 5 (g) to Nb (s) at normal atmospheric pressure is a multi-step reaction with a large amount of intermediate product (lower chloride); the reaction can be controlled at a lower hydrogen ratio (n (NbCl 5): n (H2) <1: 180) and lower temperature (<1050 ° C). The appropriate amount of inert carrier gas can improve the conversion of NbCl 5 and the yield of powder. According to the results of thermodynamics, the synthesis conditions were n (NbCl 5): n (H2): n (Ar) = 1: 120: 1 and 950 ° C. The average particle diameter was 30-50 nm and the particle size distribution was Of the nano-metal Nb powder, the corresponding NbCl5 conversion rate of 96.1%, the powder yield was 85%.