【摘要】 以Co、V、Cr的可溶性氯盐和草酸铵为原料,采用草酸盐共沉淀法制备Co、V、Cr的复合粉末的前驱体,热分解后获得Co-V-Cr复合粉末。通过DSC/TG分析对该前驱体在不同气氛(真空、氩气与氮气)中的热分解过程进行研究,通过扫描电镜观察与比表面积测试,对Co-V-Cr复合粉末的性质进行分析与表征。结果表明,不论在什么气氛下锻炼,所得Co-V-Cr复合粉末的粒径都达到纳米级,分散较均匀,V和Cr完全固溶在Co相中。前驱体合理的煅烧温度为450℃。在氩气气氛下前驱体粉末在421℃时直接分解成Co-V-Cr复合粉末;而在空气中的DSC-TG曲线在366℃出现放热峰,原因是此温度下发生氧化反应,前驱体先分解成Co-V-Cr然后被氧化。在氩气气氛下煅烧得到的Co-V-Cr复合粉末比表面积最大,为41.50 m2/g,粒径最小,平均晶粒尺寸为11~12 nm。更多还原

【Abstract】 Co-V-Cr composite powder was obtained after thermal decomposing oxalic acid salt precursor of Co-V-Cr powder prepared through oxalate co-precipitation method using Co, V, Cr soluble chloride and ammonium oxalate as raw materials. The decomposition process of precursor was studied by DSC and TG. The properties of composite were analyzed and characterized by SEM and BET. The results show that the particle size of Co-V-Cr composite powder is nanometer grade, well dispersing and V, Cr soluting in Co completely. The appropriate calcination temperature is 450 ℃.Precursor powder decompose into Co-V-Cr composite powder directly in argon atmosphere at 421 ℃; Whereas in air,DSC and TG curves present an exothermic peak at 366 ℃ indicating an oxidation reaction at this temperature, which suggests that the precursor powders first decompose into composite powder, then followed by a process of oxidation.Co-V-Cr composite powders with maximum specific area of 41.50(m2/g) and the smallest grain size of 11~12 nm are obtained in argon atmosphere calcination.更多还原