低温机械化学法制备Mo-Cu纳米复合粉末

Mechanochemical Synthesis of Mo-Cu Nanocomposites Powders at Low Temperature

摘要:

以CuMoO4-MoO3粉末为前驱体，采用机械化学-氢气共还原的方法制备出Mo-Cu纳米复合粉末。通过DSC对前躯体的制备温度进行研究，通过XRD、SEM及TEM分别对粉末的相组成、形貌和粒度进行表征，从热力学的角度对粉末的还原过程进行分析。结果表明，机械球磨可以有效地降低粉末的颗粒尺寸，增大反应面积，提高粉末还原活性，从而在低温下制备出Mo-Cu复合粉末。通过优化工艺参数，对机械球磨15 h的CuMoO4-MoO3混合粉末在680 ℃下还原，可以得到颗粒尺寸为50~100 nm的Mo-25%Cu (质量分数) 纳米复合粉末

Abstract:

Low temperature synthesis of Mo-Cu composite powders was conducted by mechanochemical treatment (ball-milling) of CuMoO4 and MoO3 mixtures followed by subsequent coreduction process. The preparation temperature of the precursors (CuMoO4-MoO3 mixtures), phases and microstructures of the Mo-Cu composites were investigated by differential scanning calorimeter (DSC), X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The thermodynamical conditions at different stages of hydrogen reduction of Mo-Cu nanocomposite powders were analyzed. Results show that the mechanochemical treatment (ball-milling) can significantly enhance the reduction activity by reducing the particle sizes of powders and hence increasing the reaction surface area, therefore giving rise to the synthesis of Mo-Cu composite powders at relatively low temperature (680 ℃). By optimizing the experimental parameters, Mo-25 wt% Cu nanocomposite powders with superfine particles ranging from 50 to 100 nm can be obtained by ball-milling for 15 h followed by reduction in hydrogen at 680 ℃