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Cryptomelane型材料的制备和表征
The Synthesis and Characterization of Cryptomelane like Material
【摘要】 MnO-4和Mn2+在酸性条件和一定温度下,用氧化还原方法制得了高结晶度的Cryptomelane型锰氧化物.用X射线粉末衍射法(XRD)、傅里叶红外光谱法(FT-IR)、热重-微商热重差热分析法(TG-DTG/DTA)、透射电子显微镜法(TEM)等方法对它进行了表征.研究表明,该Cryptomelane中可能存在两种不同热力学性质的Cryptomelane,加热Cryptomelane到600℃时,热稳定性较差的那部分转化为Mn2O3;在600~870℃,Cryptome-lane和Mn2O3共同存在;870℃,样品完全转化为Mn2O3;到940℃则Mn2O3再度失氧生成Mn3O4.另在Cryp-tomelane中存在L酸和B酸,且B酸强于L酸.
【Abstract】 A well crystallized Cryptomelane like material has been synthesized by redox reaction between Mn 2+ and MnO - 4 under acid conditions at certain temperature. XRD,FT IR,TG DATA/DTG,TEM were used to characterize the material. There are probably two types of Cryptomelane with different thermodynamic properties in our synthesized material. At 600℃,part of the Cryptomelane with worse thermal stability transformed into Mn 2O 3,the Mn 2O 3 coexisted with the another part of Cryptomelane between 600℃ and 800℃,at 870℃,the remainder completely transformed into Mn 2O 3.Both Lewis and Bronsted acid sites have been observed in Cryptomelane and the Bronsted acid is stronger than the Lewis acid.
- 【文献出处】 复旦学报(自然科学版) ,JOURNAL OF FUDAN UNIVERSITY , 编辑部邮箱 ,1999年01期
- 【分类号】O643.36
- 【被引频次】3
- 【下载频次】58