The Synthesis And Applications Of Hierarchical Macro-Mesoporous Carbon Materials

Hierarchical macro-mesoporous carbon materials continue to attract enormous research interest and have promising impact in many application areas, including catalysis, separation and supercapacitors. Based on special characters that combining high diffusion of macroporous with high surface area and high pore volume ratio of mesoporous carbon, hierarchical macro-mesoporous carbon materials have high accessibility and high storage capacity. In this paper, the dual-templating method of using asphaltene, pre-asphaltene, coal liquefaction residue in tetrahydrofuran solution and resin as four kinds of precursors, SBA-15 and F127 as mesoporous templates, and polyurethane foam and polystyrene beams as macroporous template to prepare hierarchical macro-mesoporous carbon materials has been studied. Structures and characters of products were characterized by X-ray diffraction, transmitsion electron microscope, scanning electron microscope and nitrogen adsorption. The electrochemical double layer capacitors (EDLCs) performances of products were also investingated.The results are showed as follows:1) Using PU foam and SBA-15 (lab made) as template, hierarchical macro-mesoporous asphaltene based foam (ASF), pre-asphaltene based foam (PASF) and coal-liquefaction based foam (CLF) had been synthesized. Those products have 3-D inner connected macroporous structure with ordered mesoporous pore wall. All of the three products have macropores of 300μm and mesoporous of 4-5 nm in diameter. BET surface area and total pore volume of ASF, PASF and CLF are 744 m2/g,0.64 cm3/g; 570 m2/g,0.55 cm3/g and 570 m2/g,0.48 cm3/g, respectively. This synthesis method can be used as a novel and promising way to utilize coal liquefaction residues.2) Using F127 and PS beams as templates resin as carbon precursor to investigate the variety in the preparation of macro-mesoporous carbon materials. Such hierarchical macro-meso porous carbon (HMMC) product has an ordered 3-D connected macroporous structure with about 1μm pore sizes, and the pore wall contains ordered mesopores with average pore sizes of about 5 nm. BET surface area of the product is 354 m2/g and total pore volume is 0.36 cm3/g 3) EDLCs performance of products was investigated by cyclic voltammetry and galvanostatic charge/discharge methods in three-electrode electrochemical cell system. Results show that those hierarchical porous carbon materials have excellent EDLCs characters. It has great potential in applications as electrodes of electrochemical capacitors.