Hydrogen production by catalytic decomposition of methane over Ni-Cu-Co alloy particles

A series of Ni-Cu-Co alloy catalysts with different atomic compositions were prepared by the thermal decomposition of fibrous Ni-Cu-Co oxalate precursors in methane atmosphere. The resulting porous aggregates of Ni-Cu-Co alloy particles, with crystalline sizes ranging from 12.6 to 15.9 nm, showed good catalytic activities for methane decomposition in the temperature range from 650 to 775 degrees C. The percent composition of the constituent metals in the Ni-Cu-Co alloy catalyst was a dominant parameter that could affect the catalytic activity of the catalyst. When compared with the Ni-Cu alloy, the addition of cobalt was found to inhibit the quasi-liquid phenomenon effectively. With increasing cobalt content, the catalyst stability at higher temperature was improved but further continual increase of cobalt content led to phase separation as evidenced by the X-ray diffraction (XRD) patterns. The mechanism for the stabilizing effect of cobalt is discussed. The textural properties of the carbon nano-fibres were characterized by transmission electron microscopy and XRD. (C) 2014 Elsevier B.V. All rights reserved.