Iron metal was used for hydrogen production via methane decomposition using alumina as support; furthermore, to overcome the drawback of alumina, titanium dioxide was added at 20 %, considering various calcination temperatures. The results show that adding 20 % of TiO₂ to alumina enhances the activity of catalysts for hydrogen production and stability. Carbon was produced as carbon nanotubes (CNT).

Abstract

The decomposition of methane has been chosen as an alternative method for producing hydrogen. In this study, 20 % Fe was used as the active metal part of the catalyst. To better comprehend the impact of the supporting catalytic properties, alumina and titania-alumina composite were investigated as supports. Iron-based catalysts were prepared by impregnation method and then calcined at different temperatures (300 °C, 500 °C, and 800 °C). The catalysts were examined at 800 °C under atmospheric pressure with a 15 mL/min total flow rate and 2 : 1 CH₄ to N₂ feed ratio. The textural and morphological characteristics of the fresh calcined and spent catalysts were investigated. The catalytic activity and stability data demonstrated that Fe supported over TiO₂-Al₂O₃ calcined at 500 °C performed the best of all evaluated catalysts with a more than 80 % hydrogen yield. The Raman spectra result showed that graphitic carbon was produced for all used titanium dioxide catalysts. Moreover, according to transmission electron microscopy (TEM) results, the carbon deposited on the catalysts’ surface is carbon nanotubes (CNT).