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以不同的镍基前驱物(氧化镍、乙酸镍、硝酸镍)在超临界甲醇体系中制备超细镍粉体,考察了反应体系温度、压力、反应时间以及前驱物种类对制备产物的影响。通过SEM和XRD对制备产物的形貌和物相进行表征分析。结果表明,超临界甲醇的还原性随着温度和压力的升高而显著增强;同时,在反应体系中甲醇既起到溶剂作用又起到还原剂的作用。以乙酸镍为前驱物时在250℃/9 MPa的超临界甲醇条件下即能够得到纯的超细镍粉,硝酸镍则要求超临界甲醇具有更高的温度和压力(280℃/14.0 MPa),而以氧化镍为前驱物时即使在300℃/20 MPa的超临界甲醇条件下所得产物也是镍和氧化镍的混合物。
Different nickel base precursors (nickel oxide, nickel acetate and nickel nitrate) were used to prepare ultrafine nickel powder in supercritical methanol system. The effects of reaction temperature, pressure, reaction time and precursor type on the prepared product were investigated. The morphology and phase of the prepared product were characterized by SEM and XRD. The results show that the reducibility of supercritical methanol increases with the increase of temperature and pressure. Meanwhile, methanol plays the role of solvent and reductant in the reaction system. Pure nickel powder can be obtained under the condition of 250 ℃ / 9 MPa supercritical methanol with nickel acetate as precursor. Nickel nitrate requires supercritical methanol to have higher temperature and pressure (280 ℃ / 14.0 MPa) , And the resulting product was also a mixture of nickel and nickel oxide with nickel oxide as a precursor even under supercritical methanol conditions of 300 ° C / 20 MPa.