Catalytic properties of Ni modified hexaaluminates LaNiyAl12−yO19−δ for CO2 reforming of methane to synthesis gas Original Research Article

A series of Ni-modified hexaaluminates, LaNiyAl12−yO19−δ (y = 0.3, 0.6, 0.9, 1.0), were designed as new catalysts for CO2 reforming of methane to synthesis gas. They were prepared by decomposition of nitrates and calcination at high temperature. The modifier Ni as active component was inlayed in the prepared hexaaluminate to substitute part of Al ions. The crystalline structure and properties of the hexaaluminates were characterized using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR) and thermogravimetric analysis (TGA) techniques. The results showed that a pure hexaaluminate LaNiyAl12−yO19−δ phase could form only at 0 < y ≤ 1. The reduced hexaaluminates LaNiyAl12−yO19−δ exhibited significant catalytic activities and stability for the topic reaction at high temperature, which were sensitively affected by the modifier Ni in the hexaaluminate lattices. Under the same reaction conditions, the conversions of CH4 and CO2 increased with an increase in the amount (y value) of the modifier Ni.