薄壁中孔碳材料的精细控制合成

摘要

Mesoporous carbon materials with a range of pore sizes were synthesized by a delicately controlled procedure using disordered /-alumina as template and sucrose as carbon source. Under optimized conditions, the carbon materials had narrow pore size distribution, large surface area (>1000 m2·g-1), large pore volume (up to 3.82 cm3·g-1), high mesopore ratio (>99%), and thin pore walls with thickness of 1-2 graphene layers. In the present work, we employed three types of alumina, and investigated the correlation of their texture with that of the resultant carbon materials. A mechanism for the formation of the carbon materials was proposed and tested against experimental data. A carbon sample prepared by this method can approximately duplicate the pore structure of the template, if the carbon layer in the precursor carbon-covered alumina is complete and sufficiently robust. The mesopores of the carbons had two sources, one from the removal of the template particles and the other from the original pores of the template. Calculated pore volumes strongly support the proposed mechanism.%利用γ-氧化铝为模板.精细控制合成了一系列具有不同孔径的中孔碳材料.在优化的条件下,所得的碳材料具有孔径分布窄、比表面积高(>1000 m2·g-1)、孔容大(最高3.82 cm3·g-1)、中孔率高(>99%)的特点,并且孔壁厚度仅有1-2个石墨层.选用了三种不同来源的氧化铝为模板,考察了模板与所得碳材料织构的相关性,并提出用无序模板可控制备碳材料的机理.即在碳包覆氧化铝的复合物前体中,若碳层完整覆盖氧化铝表面并且足够强韧,则所得碳材料可近似复制模板的孔结构,并且碳材料的孔一部分由去除模板所生成,另一部分来源于模板原有的孔.据此模型对所得碳材料的孔容进行了理论计算,其结果有力支持了上述机理.