The effect of adding SiO2 on the performance of Ni/MgO catalyst in the thermodynamic decomposition of methane

This paper focuses on the improvement of the catalytic activity as well as the stability of the Ni-catalysts supported on a mixed oxide of SiO2 and MgO for the simultaneous production of COx-free hydrogen and nanocarbon from methane decomposition reaction. SiO2/MgO mixed oxide was prepared via a facile co-precipitation method from magnesium nitrate and sodium silicate and used as support. Different analytical techniques such as XRD, BET, and SEM were performed for characterization of the catalysts. The prepared catalysts depicted the BET surface area ranging from 37.9 to 117.0 m2.g-1 which indicative remarkable improvements in the surface area after adding silica. SEM analysis confirmed a porous structure for the catalyst. A high productivity of hydrogen with the high methane conversion of 64% was obtained over the 50 wt% Ni/SiO2.MgO at 575 oC. Moreover, no catalyst deactivation was observed for this catalyst at a period of 600 minutes of time on stream. This is mainly referred to the presence of free NiO particles which have appropriate interaction with the support.

کلیدواژه ها:

Thermocatalytic decomposition of methane ، Nickel catalysts ، SiO2.MgO ، Co-precipitation