Carbon fibers prepared by pyrolysis of methane over Ni/MCM-41 catalyst

Abstract

The pyrolysis of CH 4 to H 2 and carbon fibers over MCM-41 supported Ni catalyst has been investigated at different temperatures. The initial conversion of CH 4 at 873 K is higher than it is at 773 K, but the deactivation at 873 K occurs rapidly. The investigations with SEM and TEM techniques indicate that the pyrolysis of CH 4 generates mainly solid carbon fibers at 773 K but mostly hollow ones at 873 K on Ni/MCM-41. Ni metal particles have hardly been found on the tip of or inside the carbon fibers. Raman spectroscopic studies suggest that the carbon fibers formed at 873 K are more graphitic than those obtained at 773 K. The temperature-programmed reactions with O 2 (TPO) and H 2 (TPH) reveal that the solid carbon fibers formed at 773 K show higher reactivity towards O 2 and H 2 than the hollow ones formed at 873 K.