Sr Promoted Ni/W-Zr Catalysts for Highly Efficient CO Methanation: Unveiling the Role of Surface Basicity.

This study explores the employment of CO methanation for carbon dioxide utilization and global warming mitigation. For the first time, in this work, we combine the interesting properties of the WO-ZrO support and the benefits of Sr to improve the performance of Ni-based catalysts in this reaction. Sr loading on 5Ni/W-Zr samples is increased to 3 wt %, resulting in improved surface basicity through strong basic site formation. After 300 min, the 5Ni + 3Sr/W-Zr catalyst exhibits high activity and stability, achieving 90% CO conversion and 82% CH yield compared to 62 and 57% on 5Ni/W-Zr. Limited sintering and absence of carbon deposits are confirmed by temperature-programmed oxidation, XRD, Raman, and TEM analyses at 350 °C for 300 min. Sr promotion creates additional CO adsorption and conversion sites, enhancing the catalytic performance.