Catalytic properties of Ni modified hexaaluminates LaNiyAl12-yO19-delta for CO2 reforming of methane to synthesis gas

A series of Ni-modified hexaaluminates, LaNiyAl12-yO19-delta (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 calcinat ion 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-r ay powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temper ature-programmed reduction (TPR) and thermogravimetric analysis (TGA) techn iques. The results showed that a pure hexaaluminate LaNiyAl12-yO19-delta ph ase could form only at 0 < y less than or equal to 1. The reduced hexaalumi nates LaNiyAl(12-y)O(19-delta) exhibited significant catalytic activities a nd stability for the topic reaction at high temperature, which were sensiti vely affected by the modifier Ni in the hexaaluminate lattices. Under the s ame reaction conditions, the conversions of CH4 and CO2 increased with an i ncrease in the amount (y value) of the modifier Ni. (C) 2000 Elsevier Scien ce B.V. All rights reserved.