Calcium-based promoter in Ni catalysts supported over nanostructured ZrO2

This study investigates the impact of CaO addition on the catalytic performance of Ni/ZrO2 materials for the dry reforming of methane. ZrO2 supports were synthesized using the co-precipitation method, wherein CaO (2 and 10 wt%) was incorporated during the initial synthesis stage. Subsequently, these supports were impregnated with 15 wt% Ni. The catalysts were characterized by X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WDXRF), temperature-programmed reduction (TPR), and Fourier transform infrared spectroscopy-DRIFTS. The catalytic evaluation was performed in a flow microreactor at 700 degrees C, using a feed gas ratio CH4:CO2 of 1. Introducing CaO enhanced the catalyst's basic sites, increasing catalytic activity. However, the catalytic performance did not correlate solely with the impregnated CaO percentages. The catalysts demonstrated varied performances, with the order of effectiveness observed as 10% CaO > 0% > 2% CaO. These findings underscore that catalysts with higher basicity also exhibited reduced carbon formation, a factor directly associated with catalyst deactivation.