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 °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. Graphical abstract: [Figure not available: see fulltext.].