Studies On Preparation And Adsorption Properties Of Mesoporous Carbons Vs A Template Method

The mesoporous dimension of porous carbons is controllable, or mesoporous carbons are orientedly prepared, which means to control the pore size to prepare the expected carbons according to its application requirement. That's why it is significant to study how prepare porous carbons with controlable mesoporous structure. The aim of this study on mesoporous carbons is to further improve its properties, and to exploit novel applications.In this thesis, firstly, porous carbons were prepared by template method, where tetraethoxy silane(TEOS) was used as the source of the silica template and phenolic resin(PF) as the carbon precursor, was suggested for the preparation of mesoporous carbons with a controllable pore structure. A precursor solution of the silica template prepared by prehydrolysis of TEOS in all acid medium was blended with phenolic resin solution. The two sol-gel reactions proceeded simultaneously under basic conditions in a sealed vessel and resulted in the formation of organic / inorganic gel. A new mesoporous carbon was obtained by dissolving the silica template with carbon net in the hydrofluoric acid after carbonization, followed by drying. It suggested that the silica templatesynthesized simultaneously with the carbon precursor polymer resulted in the controlable mesoporous structure of the resultant carbons. The sorption data overall suggests that the mesoporous structure of the carbons is originated from the silica template framework which are removed by HF, and the pore structure can be effectively tailored by the adjustment of the processing conditions.The influence of PH value of organic / inorganic gels, ratio of TEOS and PF, carbonization temperature on pore structure and adsorption property of mesoporous carbons characterized by FT-IR, N2 isothermal adsorption, SEM, and TGA so on, were systemically discussed. The results indicated that acid catalysis helps to prepare mesoporous carbons within several hours, especially when PH value is 4, mesoporous carbons possessed bigger SBet and pore volume, mesoporous percent exceeding 80%. The bigger T: P value, the larger the mesopore diameter, which is benefit to adsorption to macromolecule because its larger pore diameter is suited to macromolecule diameter, beside its larger ratio surface area and pore volume. The adsorption of them is not only correlated with the BET surface area, but also the micropore size. Ratio surface area, pore volume and adsorption capacity of mesoporous carbons carbonized at 850 °C is higher than that at other temperature. The mesoporous carbons prepared by template method exhibited a concentrated pore dimension, specifically 3-10nm, a high specific surface area, and a high mass-specific adsorption capability to formaldehyde and VB12, 682.2 mg/g and 40.8 mg/g respectively.