Controlled Synthsis Of Layered Copper-Manganese Mixed Oxide

Basing on structure cell of Layered Manganese Oxides, micro- and meso- structure design and controlled synthesis of Layered Manganese Oxides and misfit-layered copper manganese mixed oxides were investigated. The synthesized samples were studied comprehensively by XRD, FTIR, TPR, TG/DSC, TEM, Special Surface Analysis, AAS, and Micro-Reactor-Chromatography. Emphases were to study dependence of the composition, structure and properties of OL on the synthesis techniques and process.For the manganese oxides of OL structure, the alkali reaction system is the pivotal factor for the synthesis of layered manganese oxide. The wet product prepared by bubbling O2 into the mixed of NaOH and MnSO4 solution show a typical Buserite structure and transformed to Birnessite after dried. But for mixed of KOH and MnSO4, the wet and dried products have a potassium manganese oxide hydrate structure. Dry temperatures address slight effect on the formation of layered manganese oxide with some influence on the crystallization and size of layered manganese oxide, and well crystallized Birnessite can be obtained at 60℃under atmospheric condition. The amorphous copper manganese mixed oxides can be synthesized after Cu2+ was adulterated in the material solution, and translated into Cu1.5Mn1.5O4 after calcination.The study of synthesis and performance of Misfit-layered structure shows guest anion plays important rules on the ion-exchange capacity and structure of the manganese oxides of OL structure. The basal spacing of Buserite decreased after it reacted with CuSO4 solution. XRD pattern shows that only Mn3O4 existed after Buserite reacted with CuAc2 solution. The concentration of Cu2+ address slight effect on the Cu/Mn of products after ion-exchanged. Buserite transformed to Birnessite after it was dried, but the basal spacing of Cu2+ doped products decreased to 0.87nm after they were dried. Birnessite was obtained after Buserite was hydrothermal treated in distilled water, and Misfit-layered structure can be also obtained after Cu4(SO4)(OH)6 doped products hydrothermal treated in distilled water. XRD pattern shows that the crystallization of Misfit-Layered improved with the increase of Cu/Mn, but plenty of Cu4(SO4)(OH)6 can not be inserted into the layer by the process of hydrothermal when the Cu/Mn reached a certain value. TEM pattern shows that the crystals of Misfit-Layered are sheet-like, while the arrangement of the atoms is line-like and the distance between the two strong lines is about 0.46nm. Birnessite translated into Mn2O3 and Na2Mn8O16 but Misfit-Layered translated into Cu1.5Mn1.5O4 after they were both calcined. TEM pattern shows Misfit-Layered partly united together after they were calcined. Reductive process of Birnessite is complex with two reduction peaks appearance but the process of Misfit-Layered is much simple with exclusive reduction peak. When the Cu/Mn is in a suitable range, the activity of samples is stable, but when the Cu/Mn out of range, there is no active position left. After water gas shift reaction the sample from Birnessite was only MnO left,whereas Misfit-Layered were Cu and MnO. the crystallization of Misfit-Layered slightly improved with the increase of hydrothermal temperature. The drop-wise speed of the alkali solution makes no effect on the formation of Misfit-Layered by the process of pH titration.The pretreatment of Birnessite can be dramatically affecting the crystallizations of wet and dried H-Bir. The acid treatment by drop-wising HCl solution into starting materials remarkably improved the crystallization of wet and dried H-Bir. The crystallization of wet H-Bir deteriorated with the acid treatment by dumping HCl solution into starting materials. The double-layer hydrates disappeared and the crystallization deteriorated after Buserite was treated with HCl. TMACl solutions makes no effect on swelling the interlayer of dried H-Bir that was produced by drop-wising and dumping. TMAOH solutions will also not swelling the interlayer of wet and dried H-Bir that was produced by drop-wising. No matter 2d or 7d of ion-exchange time can not make the interlayer increasing. TMACl and TMAOH can not increase the basal spacing of Buserite, but the basal spacing of Buserite translated into 0.7nm after Buserite reacted with TMAOH. TMACl and TMAOH also can not increase the basal spacing of H-Bus.