中空球形碳酸锰合成及热分解制备MnO_(x)研究

Synthesis of Hollow Spherical Manganese Carbonate and Its Thermal Decomposition for Preparation of MnO_(x)

以MnC_(4)H_(6)O_(4)·4H_(2)O和NH_(4)HCO_(3)为原料,通过水热法制备了中空球形结构MnCO_(3)。基于MnCO_(3)在空气、氩气及氢气气氛中的TG-DSC分析结果,研究了MnCO_(3)在400~800℃、不同气氛中焙烧2 h后的产物变化。结果表明,空气中焙烧产物主要为MnO_(2)及Mn_(2)O_(3),氩气条件下焙烧产生的MnO被氧化为Mn_(3)O_(4),氢气条件下焙烧产物主要为MnO。不同气氛条件下焙烧后获得的MnO_(x)基本保持MnCO_(3)的形貌特征,且表面结构明显改善,有利于后续MnO_(x)的功能化应用。通过调控MnCO_(3)形貌及气氛焙烧条件,可制备不同形貌、价态、成分的锰氧化物及复合材料。

Hollow spherical manganese carbonate was successfully synthesized with hydrothermal method with MnC_(4)H_(6)O_(4)·4 H_(2)O and NH_(4)HCO_(3) as raw materials.Based on the TG-DSC analysis of MnCO_(3) under air,argon and hydrogen atmospheres,the phases of the powders obtained after 2-hour roasting at 400~800℃under different atmospheres were studied.Results show that the product obtained from the roasting under air condition is predominantly MnO_(2) and Mn_(2)O_(3),and the MnO generated from roasting in argon atmosphere is oxidized to Mn_(3)O_(4),while the products obtained from the roasting in hydrogen is mainly MnO.It is shown that the MnO_(x) obtained after roasting in different atmosphere almost maintain the same with MnCO_(3) in morphology,but have a great improvement in the surface structure,which is beneficial to the following functional application of MnO_(x).It is concluded that MnO_(x) with different morphologies,valence states and compositions can be prepared by adjusting the morphology of MnCO_(3) and roasting atmosphere.