Coke formation during CO2 reforming of CH4 over alumina-supported nickel catalysts

Carbon dioxide reforming of methane to synthesis gas over Ni supported alumina catalysts was investigated at atmospheric pressure. Two supports: high surface area γ-Al2O3 (SA-6175) and low surface α-Al2O3 (SA-5239) were used for the preparation of catalysts by the wet impregnation method. The reforming reactions were carried out using (CO2:CH4) feed ratio of 1:1, and reaction temperatures 500, 600, 700 and 800 °C. Influences of Ni loading, catalyst stability, coke deposition and synthesis gas ratio (H2/CO) were studied. Spent and fresh catalysts calcined at 900 °C were characterized by XRD, SEM and TGA techniques. It was observed that increasing Ni loading increases the formation of carbon. For high surface area catalyst, at low Ni loading, no coke formation on the catalyst was obtained. Similarly, no carbon formation was observed for low surface catalyst at 800 °C reaction temperature with feed ratio of 1.3/1.0