Preparation Of MoO 3 Intercalation Composites And Study Of Their Catalytic Properties

?-MoO₃ is a typical layed semiconductor material, due to its rich electromagnetic, optical, mechanical and thermal stability, it becomes the more concerned functional material. The layers of ?-MoO₃ are stacked by weak vander Waals forces, which is easily destroyed through insertion of guest molecules to obtain functional MoO₃ intercalated composite materials. For the designed MoO₃ intercalated composite material, it is expected to extend or enhance its performance through further processing such as calcination, which is of great significance for developing the applications of the materials. While different calcinated conditions can make the structure, com-position and morphology of the obtained composite materials change, which may directly affect its performance, at present, the reports of this aspect is less, the thesis synthesized MoO₃/dodecylamine ?DDA? and calcinated it, and we investiged the effects of different calcinated conditions on the structure, composition and morphology on the obtained composite materials.According to the literature, the electrochemical properties of heteroatoms-doped ?such as N, B, F, P, S, ect? carbon materials are superior than the undoped. Nowadays, the designed and synthesized guest molecules in MoO₃ intercalated composite material are mainly N, O, S heteroatoms, in order to optimize the materials'performance and explore some of its untapped features and applications with a greater extent, it is very necessary to design some new intercalated composite materials. The thesis designed and synthesized a novel MoO₃/4-bromobenzyl phosphonic acid ?4-BBPA? intercalated composite material, and carried on the calcinated process to study the changes of the structure and composition in the composite material.In recent years, there are a very wide range of researches about electrical perfor-mance of the MoO₃ intercalated composite materials, while the catalytic research is very limited, the thesis used the composite materials as catalysts, and studied the influences of different calcinated conditions on its catalytic performance.There are three parts in the thesis, the specific work is as follows:?1? MoO₃/DDA intercalated materials were synthesized via direct thermal treatment followed by calcination to obtain MoO₃/C-N hybrid materials at N2 atmosphere. Prepared hybrid materials were characterized by powder XRD, SEM,TEM, XPS and Raman spectroscopy to study the influences of the calcinated conditions ?such as calcinated temperature, calcinated heating rate, calcinated time? to the structure and composition of these materials. The results exhibited the order-disorder-order changes of the crystal structure during the calcinated temperature from 400? to 800?, valence of some Mo was reduced from +6 to+4 or +2. XRD patterns showed that calcinated heating rate had almost no effect on the composite structure; crystal MoO2 was produced at 600? in N2 atmosphere with the increase of calcinated time, and while crystal Mo2C was formed with the increase of calcinated temperature. SEM and TEM images clearly showed that the MoO₃ layer structure was kept as the calcinated temperature below 600?. As the calcinated temperature more than 600?, the carbonization effect of carbonaceous molecules and the enormous loss of gas molecules made the structure collapse into sheet-like structure. In addition, the carbon and nitrogen elements were detected on the surface of molybdenum oxide by the element mapping of TEM.?2? Two kinds of guest molecules containing P atom such as dodecylphosphonic acid ?DDPA? and 4-BBPA were designed and synthesised, MoO₃/4-BBPA intercalated materials were prepared via ion exchange method followed by calcination to give MoO₃/C-P hybrid materials at N2 atmosphere. Powder XRD, SEM, TEM, XPS and Raman spectroscopy were used to characterize these hybrid materials to study the influences of the calcinated temperature to the structure and composition of these materials. The results showed that the 4-BBPA was inserted MoO₃ layers with double molecular layer at less than 90 angle, DDPA can not be inserted into the interlayer of MoO₃. The results exhibited the order-disorder changes of the crystal structure during the calcinated temperature from 400? to 800?, valence of some Mo was reduced from+6 to+5. When the calcinated temperature was below 200?, the MoO₃ layer structure was not affected by the dehydration reaction between the 4-BBPA. When calcinated temperature was increased from 200? to 700?, the Br element in 4-BBPA molecule was eliminated and 4-BBPA molecules were carbonizated. When the calcinated temperature was higher more than 700?, decomposed MoO₃ resulted in the destruction of layers of MoO₃.?3? The MoO₃/C-N hybrid materials obtained under different calcinated conditions were used as catalyst for the oxidation of benzyl alcohol. The catalytic results exhibited that the MoO₃/C-N hybrid materials formed at 600? in 2 h had efficiently high selectivity and relative stability for catalyzing benzyl alcohol to benzaldehyde.