Development of nickel catalysts supported on titanium dioxide derived from Thai leucoxene for hydrogen production via methane decomposition

Abstract

This study investigated the development of nickel catalysts supported on titanium dioxide derived from Thai leucoxene mineral (Ni/TiO₂-Leucoxene) for hydrogen production via methane decomposition, and compared their properties and performance with those of nickel catalysts supported on commercial titanium dioxide (Ni/TiO₂-Commercial). The catalysts were prepared by the wet impregnation method with a nickel loading of 30 wt%. Their physicochemical characteristics were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The catalysts were then tested in a fixed-bed reactor at 600 and 650 °C under atmospheric pressure, and the composition of the product gases was analyzed by gas chromatography. XRD analysis of the leucoxene-derived support revealed the presence of TiO₂ together with oxide phases of other elements, including Fe₂O₃ and SiO₂. After catalyst preparation, NiO was detected in both catalysts. Scherrer analysis showed that the average crystallite size of NiO in Ni/TiO₂-Leucoxene was 11.9 nm, which was smaller than that of Ni/TiO₂-Commercial at 14.6 nm. SEM images showed that the Ni/TiO₂-Leucoxene catalyst possessed a rod-like morphology with observable interparticle voids, in contrast to the densely agglomerated particles observed for the Ni/TiO₂-Commercial catalyst. The methane decomposition results demonstrated that Ni/TiO₂-Leucoxene provided significantly higher methane conversion than Ni/TiO₂-Commercial. The maximum methane conversion of 98.7% was obtained at 650 °C after 90 min of reaction. These findings suggest that Thai leucoxene mineral has strong potential as a low-cost support material for catalysts in hydrogen production from methane.