| This paper mainly consists of two sections, review and experiments. Thecharacter of structure, synthesis methods, properties, applications and the developmentof porous manganese oxides were reviewed in the first section (Chapter 1). The novelsynthesis method of a SiO2-TiO2 mixed pillared porous manganese oxide with a layeredstructure was described in the experiments section (Chapter 2, and 3), in which H-typelayered manganese oxide was acted as precursor, a mixture solution oftetraethylorthosilicate and titanium isopropoxide was functioned as pillaring agent.Meanwhile, the synthesis conditions were optimized and effects of reaction medium onSiO2-TiO2 mixed pillared structure were also investigated.The novel synthesis method of SiO2-TiO2 mixed pillared porous manganese oxidewith a layered structure was described in Chapter 2. H-type layered manganese oxidewas obtained by an acid exchange mechanism from its Na-type precursor, which wassynthesized by the oxidation precipitation method in sodium hydroxide solution. H-typelayered manganese oxide was reacted with dodecylamine ions, which were able to beintercalated into the interlayer of H-type layered manganese oxide by an ion-exchangemechanism, forming a swelled layered manganese oxide. The swelled layeredmanganese oxide was stirred with a mixed solution of tetraethylorthosilicate andtitanium propoxide at a molar ratio of Si/Ti=1:1, followed by a solvethermaltreatment at 160℃for 48 h, then the silicate and titanate mixed pillared manganeseoxide was synthesized. A SiO2-TiO2 mixed pillared porous manganese oxide wasobtained by heating the silicate and titanate pillared manganese oxide in the air at 200℃for 2 h, which still maintained a layered structure and had a basal spacing of 1.43 nmas well as a BET area of 98 m2/g. The obtained materials at different stages werecharacterized by XRD, DSC-TGA, SEM, IR, N2 adsorption-desorption and elementanalysis.Based on the synthesis of SiO2-TiO2 mixed pillared porous manganese oxide, wediscussed systematically the effects of reaction conditions on the structure and property of the obtained materials. Alkylamine swelled layered manganese oxides with differentbasal spacing were obtained by reacting H-bimessite with butylamine, octylamine, anddodecylamine, respectively. The results indicated that the basal spacing of thealkylamine intercalated products connected with the chain length of intercalatedalkylamine. The different alkylamine intercalated layered manganese oxides weredispersed into the mixture solution of tetraethylorthosilicate and titanium propoxide atthe same molar ratio, and then the suspensions were solvethermally treated at the sametemperature. The diffraction peaks in intensity gradually increased and the basal spacingof obtained materials little shifted to lower 2θangles with the increase of alkylaminechain length. At the same time, we studied the effect of the Si/Ti molar ratio in themixture solution of TEOS and TIIP on the structure and property of the obtainedmaterials. Results showed that the basal spacing increased slightly with the increase ofthe Si content in the mixture solution of TEOS and TIIP, indicating that the molar ratioof Si/Ti had weak influence on the structure of the obtained materials. In addition, theeffect of solvethermal temperature on crystallinity and thermal stability of the obtainedmaterials were also studied. The results showed that all obtained products had a layeredstructure, but the basal spacing increased with the increase of the solvethermaltemperature. The layered structure of the obtained SiO2-TiO2 mixed pillared layeredporous manganese oxide could be stabilized to 300℃and was destroyed above thistemperature. It was found that the basal spacing, the intercalated amount of silicon andtitanium, and the thermal stabilization of the finial products were related to the H2Ocontent existed in the interlayer of alkylamine swelled layered manganese oxides. TheSiO2-TiO2 mixed pillared porous manganese oxide could be synthesized basis on thesystematic research of the influencing factors for the pillared porous manganese oxides.In Chapter 3, ethanol was added into the mixture solution of tetraethylorthosilicateand titanium propoxide in order to investigate its effect on the property and structure ofSiO2-TiO2 mixed pillared porous manganese oxides. Meanwhile, the effects of theethanol volume, mixed reactant medium compositions and the kind of alkylaminemolecules on the structures and properties of the obtained pillared materials also weresystematically investigated. The obtained materials were heated at some temperature;their thermal stability was discussed via the XRD analyses. Research results showedthat the thermal stability of the obtained materials was improved by adding ethanol of certain amounts in the mixture solution. With the increase of ethanol volume, thediffraction peaks of the obtained materials in intensity decreased, while their basalspacing increased. The thermal stability became weaker with the increase of ethanolvolume. At the same time, the basal spacing and the thermal stability of the obtainedmaterials increased with the increase of the Si/Ti molar ratios. On the other hand, thebasal spacing of the obtained materials increased with the increase of CnH2n+1NH2 chainlength, while their thermal stability hardly increased. The obtained materials at differentstages were characterized by XRD, SEM and IR.
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