Microporous Silicon Oxycarbide (SiOC) materials are fabricated by pyrolysis treatment of polysiloxane precursors. The thermal treatment of the precursors was carried out in a temperature range from 500 deg C to 1000 deg C in flowing nitrogen atmosphere. A high degree of microporosity is reached depending on the temperature applied; maximum BET specific surface areas of nearly 450 m~2/g are achieved at a pyrolysis temperature of 600 deg C. These large surface areas can be realized in high volume components if the formaiton of orientated pore channels is additionally provided by incorporation and first step decomposition of polymer fibers. Heat treatment to higher temperature leads, however, to micropore collapsing and loss of inner surface area. This degradation can efficiently be hindered by the modification of hte polymer. For this purpose various alkylsilane additives and a further portion of prepyrolized filler to be incorporated in the green body are used. The tmeperature of pore collapsing can be sifted to higher values and large inner surface areas are still being kept at a level of higher than 160 m`2/g after heat treatment at 1000 deg C. Mercury (Hg)-porosimetry and gas adsorption measurements are applied to characterize the porosity and the hgih BET surface areas and DFT derived pore distributions.
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