Hydrogen and Carbon Nanofiber Coproduction by Methane Decomposition over Ni/Diatomite Catalysts

Catalytic decomposition of methane (CDM) is a unique potential technology, producing only CO_x-free hydrogen and solid carbon. Reducing the cost of catalysts and finding application scenarios for the large amount of carbon byproducts are unavoidable issues in the CDM application process. Therefore, natural diatomite materials, which are abundant and environmentally friendly, were used as catalyst support in this paper. Nickel phyllosilicates were synthesized on the surface of diatomite by a hydrothermal method, and well-dispersed Ni/diatomite catalysts were obtained by high-temperature reduction. The maximum methane conversion of the catalyst was 30% at 500 °C, and the CNFs were uniformly adhered to the diatomite support surface. Both metal loading and temperature could affect hydrogen yield and structural characterization of CNFs. Theoretically, this CNFs/diatomite composite can be added to natural rubber as a filler and enhance its heat dissipation properties. In addition, no CO₂ production was detected during the reaction. Our results provide new insights into the preparation of catalysts and carbon production application of CDM, which can further improve the economics of CDM.