摘要：以偏钒酸铵、二氧化钛及石墨为原料，采用碳热还原法， 成功制备 V8C7 粉体；采用 X 射线衍射物相分析、热重-差热分析、扫描电镜形貌观察以及粒度分析等方法研究偏钒酸铵碳热 还原制备 V8C7 的还原过程，优化了配碳系数。结果表明：低温一次还原以偏钒酸铵脱氨脱水分解反应以及低价钒氧化物的形成为主；高温二次还原以钒氧化物向非化学计量 VCx 的转化为主；随着配碳系数的增加，反应产物 VCx 的晶格常数不断增大；当反应温度为 1 500 ℃、配碳系数为 0.9 时可获得钒原子和碳原子有序排列的单相 V8C7，粒径约为 2.7 μm。 

关键词：偏钒酸铵；碳热还原；配碳系数

Abstract：V8C7 powders were prepared by the carbothermal reduction method taking ammonium metavanadate，titanium dioxide and graphite as raw materials. The reduction process of ammonium metavanadate was investigated with combination of XRD，TG -DSC，SEM and particle analysis methods and the carbon coefficient was optimized. Results show that in the period of once low-temperature reduction， major reactions are decomposition of ammonium and formation of vanadium sub-oxides. During the second high-temperature vacuum reduction，the vanadium oxides convert to the reduction products of non-stoichiometry VCx. The lattice constants of VCx increase with carbon coefficient increasing. When the reaction temperature is 1 500 ℃ and the carbon coefficient is 0.9， single phase V8C7 is obtained with orderly arrangement of vanadium atoms and carbon atoms. The grain size is about 2.7 μm. 

Keywords: ammonium metavanadate；carbothermal reduction；carbon coefficient