Progress Of Preparation Of Carbide-derived Carbon And Application In Gas Storage

Carbide-derived carbons, referred to as CDCs, are based on the carbide as precursor, a kind of new carbon material from the lattice by the extraction of non-carbon elements. In this paper, binary carbides and ternary carbides were introduced as precursors to make carbide-derived carbons. Several names in Chinese of carbide-derived carbons were summarized. Preparation processes and the principle of high-temperature Cl2-etching in a tube furnace were elaborated. We summarized structure and properties of carbide-derived carbons, focused on the latest research results in the fields of hydrogen/methane storage and supercapacitor electrode materials.The purpose of this work is to prepare carbide-derived carbons with chlorination of TiC, Ti₃AlC₂ or Ti2 SnC at high temperature. The preparation process and the structure of carbide-derived carbons were studied. In the process of preparing carbide-derived carbons, different carbide-derived carbons from TiC, Ti2 SnC or Ti₃AlC₂ were obtained by controlling the reaction temperature. The structures of carbide-derived carbons were determined with X-ray diffraction（XRD） and Raman spectroscopy snalysis. The morphologies and pore size distribution of carbide-derived carbons were analyzed by scanning electron microscope（SEM）, transmission electron microscopy（TEM） and Nitrogen sorption technique.The results indicated that TiC-derived carbons were mainly composed of amorphous carbon and graphite. However, the higher the chlorination temperature was, the more significant the graphitization was. The particle size from CDC prepared by high-pure Cl2 and the particle size of the raw material TiC retain consistent, but as the temperature increases, the particles will gradually be decomposed into smaller particles. The pore structure characteristics of CDC at various temperatures were studied by using N2 adsorption technique. By analyzing adsorption-desorption isotherms, BET specific surface area was up to 1677 m2/g, and the pore size is mainly distributed in 0.7-2.0 nm.In this paper, carbide-derived carbons were successfully synthesized from Ti₃AlC₂ precursor by chlorination with freshly prepared Cl2 at temperatures between 500 oC and 1000 oC in a tube furnace. Carbide-derived carbons prepared via chlorination at high temperature cosists of amorphous carbon and graphite. There was the obvious trend of graphitization in carbide-derived carbons synthesized at higher temperature. And the degree of order of graphitic structures increased with increasing temperature. The results showes that carbide-derived carbons particles retained layer structure of raw Ti₃AlC₂ precursors, and particles broke into single layers and/or multilayers. The pore structure characteristics of carbide-derived carbons chlorinated at 700 oC, 800 oC and 1000 oC were researched by using N2 adsorption technique. Meanwhile, influence of the air tightness of the chlorinating setup on synthesis of carbide-derived carbons was also studied.Here we report the synthesis of nanoporous carbide-derived carbons from a new precursor, titanium tin carbides（Ti₂SnC）, via chlorination at 400 oC-1100 oC. At low chlorination temperature（400 oC-500 oC）, as-synthesized carbide-derived carbons mainly consisted of amorphous carbon and chlorides. As the chlorination temperature increased up to 600 oC, chlorides disappeared, and main composition of carbide-derived carbons was amorphous carbon. At high chlorination temperature, there was a trend of graphitization. The microstructure of carbide-derived carbons was observed and characterized by scanning electron microscopy, transmission electron microscopy, N2 adsorption technique as well as high temperature and high pressure gas adsorption analyzer. Some graphite-like sheet structures in carbide-derived carbons were found. The storage capacity of carbide-derived carbons was ²06 cm3/g（ ¹5 wt.%） for methane at 60 bar and 457 cm3/g（ ⁴.1 wt.%） for hydrogen at 45 bar. Ti₂SnC-CDC is a novel and promising material for hydrogen / methane storage.