A Study on Mono and Mixed Nano-supported Co-based Catalysts for Dry Reforming of Methane

Abstract

Effect of calcination temperature on Co-based catalysts was studied in order to evaluate the modifications in structural and catalytic properties for catalytic reforming of CH₄ with CO₂ . In this regard, two sets of mono (i.e., CeO₂ and ZrO₂ ) and mixed nano-supported (i.e., CeO₂–ZrO₂ ) cobalt-based catalysts, calcined at two different temperatures (500 and 900 °C), were prepared. To evaluate the catalytic activity of the prepared catalysts, CO₂–CH₄ reforming reaction was performed in a micro tubular reactor under atmospheric conditions (1 atm) and at different reaction temperatures ranging from 450 to 800 °C. For stability evaluation, the time on stream experiments, under similar reaction conditions, was conducted at 700 °C for 9 h. Furthermore, for selected catalysts the effect of reactants feed ratio (CO₂ /CH₄ ) and gas space velocity (GSV) were also studied. Various techniques such as N₂ adsorption–desorption isotherm, temperature-programmed reduction (TPR), temperature-programmed desorption (TPD), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were used to characterize the prepared catalysts. It was found that the use of a specific calcination temperature in the pretreatment step had a strong influence on catalytic activity, stability, and amount of carbon deposition over catalyst surface in the dry reforming of methane. Additionally, the study revealed that the catalysts calcined at 500 °C had better activity and stability than those calcined at 900 °C.