Gasification behavior of catalytic filamentous carbon

The paper reports on the effect of the catalytic filamentous carbon (CFC) gasification on its textural properties. CFC samples were prepared by methane decomposition over metal catalysts (Ni, Co, Ni–Cu, Fe–Co-alumina) at 500–625 C. With respect to the ease of hydrogasification, CFC samples of different types can be arranged in the following order: CFC (Co)>CFC (Fe–Co) ¼ CFC (Ni)� CFC (Ni–Cu, 575 C). The order of their activity in oxidation with CO2 is: CFC (Co)>CFC (Ni)>CFC (Ni–Cu, 575 C)� CFC (Fe–Co). When all studied types of CFC are activated in the presence of CO2 or H2, changes in the volume of micropores and fine mesopores (3–4 nm) are minimal and do not depend on the treatment conditions. The main observed changes are related to the development of large mesopores, macropores and increase of the CFC surface area by a factor of 1.1–1.5. The development of large mesopores with D > 10 nm appears to result from gasification of less ordered graphene packages of the filaments with sizes about 10–30 nm. A slight increase of the microporosity is observed after the CFC treatment with HNO3 at 100 C. 2004 Elsevier Ltd. All rights reserved.