Carbon deposition and catalyst stability over La₂NiO₄/γ-Al₂O₃ during CO₂ reforming of methane to syngas

The use of 9% La₂NiO₄/γ-Al₂O₃ (9NLA) as a catalyst for CO₂ reforming of methane to syngas has been investigated in a fixed-bed reactor. The results revealed that the yields of CO and H₂ over a 800°C calcined 9NLA catalyst were remarkably higher than those over a 500°C calcined one. The BET data confirmed that the properties, such as specific surface area, pore volume and average pore diameter, of a used and a regenerated catalyst were similar to those of a fresh catalyst. Temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) results indicated that the activity of the catalyst depended largely on the degree of catalyst reduction, as well as on the dispersion of metallic nickel. The results of X-ray diffraction (XRD) and temperature-programmed oxidation (TPO)-MS studies demonstrated that the formation of carbon species on the catalyst could be related to the structure and surface composition of the catalyst. With the rise in temperature for catalyst calcination, there was a decline in coke formation due to the formation of a stable NiAl₂O₄ spinel structure. Published by Elsevier Science B.V.