Synthesis of nanoporous carbon with controlled pore size distribution and examination of its accessibility for electric double layer formation

A new template approach is reported for the synthesis of nanoporous carbon. In contrast with previous template methods, the present one combines the synthesis of template, the introduction and formation of carbon into one step. This is achieved by simultaneous pyrolysis of Fe(CO)(5) and C2H2 to form the Fe template in situ with the formation of carbon. Additionally, by simply supplying Fe(CO)(5) and C2H2 at different ratios, the proportion and particle size of the Fe template can be altered. Consequently, nanoporous carbons with different pore sizes can be prepared after the Fe particles have been removed by HCl treatment. Under the present experimental conditions, a microporous carbon is demonstrated having a surface area of 602 m(2)/g and pore sizes mainly in the range of 0.5-1.2 nm, and a mesoporous carbon having a surface area of 880 m(2)/g and pore sizes mainly in the range of 2-10 nm. As an example for potential applications, the presence of mesopores in the mesoporous carbon is shown to have larger capacitance values than the microporous carbon. This may result from the fact that the presence of mesopores facilitates the electrolyte migration into the carbon interior. (C) 2007 Elsevier Inc. All rights reserved.