Preparation of Porous Carbons

The polymer/zeolite host-guest precursor for preparation of porous carbon can also be obtained through direct contact of monomers in a carrier gas with zeolite molecular sieves followed by polymerization. For example, propylene can enter into zeolite Y under the carriage of N2 and polymerize to form polypropylene. After pyrolysis, the polypropylene undergoes carbonization, and the host zeolite framework of the carbonization product can be removed by dissolution in acids, leaving carbon material with characteristic pores.[93] However, the pore-size distribution of the porous carbons obtained through this approach is not uniform, and hence they are hardly used as molecular sieves for sieving small molecules. 

Several reviews covering the synthesis, properties and applications of porous carbons, especially mesoporous carbon materials, can be found in the literature. In this chapter, we summarise the recent developments in the synthesis and characterisation of templated porous carbon materials. Particular attention is paid to the synthesis of structurally ordered porous carbon materials with narrow pore size distribution via both hard and soft template methods. We especially emphasise those so-called breakthroughs in the preparation of porous carbon materials. The chapter is divided into three sections according to the pore size of carbon materials we first consider the synthesis of microporous carbon materials using zeolites and clays as hard template, then summarise the preparation of mesoporous carbon materials via both hard template and self-assembly... 

Sakata Y, Muto A, Uddin MA, Suga H (1999) Preparation of porous carbon membrane plates for pervaporation separation applications. Sep Purif Technol 17 (2) 97-100 Clint JH, Lear AM, Oliver LF, Tennison SR (1992) Membranes. EP Patent 0,474,424 Katsaros FK, Steriotis TA, Stubos AK, Mitropoulos A, Kanellopoulos NK, Tennison S (1997) Fligh pressure gas permeability of microporous carbon membranes. Microporous Mater 8 (3) 171-176... 

Sakata Y, Muto A, Uddin MA, Suga H (1999) Preparation of porous carbon membrane plates... 

Kartel MT, Sych NV, Tsyba MM, Strelko W (2006) Preparation of porous carbons by chemical activation of polyethyleneterephthalate. Carbon 44(5) 1019-1022... 

Morishita T, Soneda Y, Tsumura T, Inagaki M (2006) Preparation of porous carbons from thermoplastic precursors and their performance for electric double layer capacitors. Carbon... 

EPR has been observed and studied in porous carbons by numerous authors 178-182). The carbons studied have been prepared by pyrolysis of organic material such as dextrose 180), coal 181), and natural gas or oils 181,182). Porous carbons are of considerable technological importance and show catalytic activity for the ortho-parahydrogen conversion, the hydrogen-deuterium reaction, and many reactions of inorganic complex ions 156). Relationships between the characteristics of the EPR absorption and the catalytic activity of porous carbons for the o-p Hj and Hj-D reactions have been demonstrated by Turkevich and Laroche 183). 

Activated carbon is prepared by oxidation of porous carbon and contains significant amounts of oxygen. 

The resorcinol-formaldehyde polymers have been used to prepare highly porous carbon materials, by controlled pyrolysis in an inert atmosphere [144,154], The microstructure of the carbon is an exact copy of the porous polymer precursor. Poly(methacrylonitrile) (PM AN) PolyHIPE polymers have also been used for this purpose. These monolithic, highly porous carbons are potentially useful in electrochemical applications, particularly re-chargeable batteries and super-capacitors. The RF materials, with their very high surface areas, are particularly attractive for the latter systems. 

The physical and chemical activation processes have been generally employed to prepare the porous carbons.18"35 However, the pore structures are not easily controlled by the activation processes and the size of the pores generated by the activation processes is limited to the micropore range only. Recently, much attention has been paid to the synthesis of meso/macroporous carbons with various pore structures and pore size distributions (PSD) by using various types of such inorganic templates as silica materials and zeolites.17,36 55... 

The structure of this review is as follows in Section II, the activation and templating methods for preparing the porous carbons are briefly summarized. Section III surveys the structural characteristics of the porous carbons by using gas adsorption method. In Section IV, the molecular probe method and the image analysis method for quantitative characterization of the pore surface irregularity and the size distribution irregularity based upon the fractal theory are discussed in detail. Section V is devoted to... 

Figure 5. TG plot for samples of porous carbon nanofibers grown from acetylene on mechanochemically prepared catalysts ...

Antolini, E. Ferretti, M. Gemme, S. Preparation of porous nickel electrodes for molten carbonate fuel cells by non-aqueous tape casting. J. Mater. Sci. 1996, 31 (8), 2187-2192. 

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