Preparation of nickel catalysts supported on CaO.2Al_2O_3 for methane reforming with carbon dioxide

摘要

Nanocrystalline calcium aluminate (CaO.2Al_2O_3) was prepared by a simple co-precipitation method using Poly (ethylene glycol)-block-poly(propylene glycol)-block polyethylene glycol) (PEG-PPG-PEG, MW:5800) as surfactant and employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by X-ray diffraction (XRD), N_2 adsorption (BET), Temperature programmed reduction and oxidation (TPR-TPO) and Scanning electron microscopy (SEM) techniques. The results showed that the prepared support has a high potential as support for nickel catalysts in methane reforming with carbon dioxide. The results showed high catalytic activity and stability for the prepared catalysts. Among the prepared catalysts 15% Ni/CaO.2Al_2O_3 was the most active catalyst and showed the highest affinity for carbon formation. In addition, 7% Ni/CaO.2Al_2O_3 possessed high catalytic stability during 50 h time on stream. The TPO analysis revealed that increasing in nickel content increased the amount of deposited carbon over the spent catalysts. SEM results detected only whisker type of carbon for all spent catalysts.