不同粒径氧化铜的制备及其氢还原动力学研究

Study on precipitation of different size CuO and its hydrogen reduction kinetics

以CuSO4.5H2O和NaOH为原料制备0.1mol·L-1CuSO4溶液和4mol·L-1NaOH溶液,采用沉淀法制备Cu(OH)2纳米粉末,然后分别在200℃,500℃,900℃温度下分解Cu(OH)2得到不同粒度的氧化铜粉体.在氢气中,以15℃.min-1升温速率,用SDT2960Simulta-neousDSC-TGA差热-热重分析仪测定TG-DTA曲线,并进行动力学计算.结果表明:氧化铜粉体的形貌近似为球形,粒径分别为50,150,400nm;DTA峰值温度分别为258.90℃,279.17℃,364.80℃,随粒径的增大而提高;表观活化能分别为173.39,461.54,534.80kJ·mol-1,随粒径的增大而增大;频率因子分别为1.15×1018,2.49×1045,2.54×1045,随粒径的增大而增大;反应级数分别为1.16,1.15,1.03,随粒径的增大而减少.

The 0.1 mol·L-1 CuSO4 liquor and 4 mol·L-1 NaOH liquor were prepared by CuSO4·5H2O and NaOH as raw materials. The nano-Cu（OH）2 particles were prepared by chemical precipitation. The different size CuO particles were prepared by decomposition reaction at 200℃, 500℃, 900℃. The TG-DTA curves were obtained by SDT- 2960 Simultaneous DSC-TGA analysis apparatus, temperature velocity 15℃·min- 1 and H2 as deoxidize gas. The ki- netics analyse was by DTA-TG curves with. The results indicate that the form of CuO was almost sphericity, the CuO size was 50,150,400 nm. The DTA peak value temperature was respectively 258.90℃ ,279.17℃,364.80 ℃, and increased with the size of CuO. The apparent activation energy was respectively 173.39,461.54,534.80 k J·mol-1, increaseing with of size of CuO. The frequency gene was respectively 1.15 × 10^18, 2.49 × 10^45, 2.54 × 10^45. The reaction progression was respectively 1.16, 1.15,1.03, decreasing with the size of CuO.