Preparation Of Carbon-containing Nanoporous Materias And Their Application In CO₂ Immobilization

Greenhouse effect has serious impacts on our living environment.CO₂ is the main component of greenhouse gas.Only limiting the emission of CO₂ is not the fundamental solution.Therefore,the development of CCSU?Carbon Dioxide Capture,Storage and Utilization?have attracted more and more attention.Based on the previous works,the microporous carbon material,which has the matched pore parameter with the kinetic size of carbon dioxide,was introduced into the mesoporous silica.Then,the hierarchical porous carbon/silica composite with abundant micropores and ordered mesoporous structure were prepareded and used as the CO₂ adsorbent and catalyst carrier for ionic liquid,which was employed to catalyze the cycloaddition reaction of carbon dioxide with propylene oxide?PO?.On the other hand,the adsorption capacity of the material was improved by the doping of nitrogen heteroatom which has the ability to combine with carbon dioxide.Main results are summarized as follows:?1?Hierarchical porous carbon/silica composite was prepared by one step sol-gel method,using cationic surfactant sixteen alkyl three methyl bromide?CTAB?as template,resorcinol formaldehyde?RF?as carbon source and ethyl orthosilicate?TEOS?as inorganic precursor.The material has rich microporous structure and ordered mesoporous structure,and the co-condensation of carbon and silica in the molecular scale was achieveed.By controlling the initial amount of RF and TEOS,the proportion of carbon and silica content could be adjusted,and the morphology of the material was changed from the bulk material to the spherical morphology with the increased amount of RF,accompanied by the decreased order degree of the mesopore.This is mainly because that the RF was not only a carbon source but also affected the the arrangement of template micelles and took part of the role as co-template.?2?The solid catalyst was prepared taking the carbon/silica composite material as the carrier and the ionic liquid 1-?trimethoxysilyl?propyl-3-methylimidazoliumiodide as a catalytic active component through grafting,and used as catalyst in the cycloaddition reaction of CO₂ to epoxide propane.The catalyst generally showed the higher activity than the homogeneous phase,and the highest yield could reach 93%and even after 8 times cycles,it can still maintain good catalytic activity.?3?The eggshell shaped hollow carbon spheres containing rich nitrogen were prepared through the hard template method,using 3-aminophenol formaldehyde?APF?as carbon source and low cost nontoxic ethyl orthosilicate?TEOS?as pore producer.The adsorption capacity reached 3.19 mmol/g at 273 K and 1 atm,and the adsorption capacity remained high after 5 times recycling.?4?Various means of characterizations were used to characterize the structures,chemical properties and performance of materias,such as SEM,TEM,X-ray diffraction?XRD?,fourier transform-infrared spectroscopy?FT-IR?,²⁹Si-NMR,elemental analysis,gas adorption and so on.