Tailoring strontium-promoted alumina-zirconia supported Ni-catalysts for enhanced CO2 utilization via dry reforming of methane: Sr loading effects and process optimization

An urgent need exists in the dry reforming of methane (DRM) community for a cost-effective and high-performance catalyst system to facilitate the industrial production of H₂-rich syngas. In this study, we propose a catalyst composed of a 10 wt% ZrO₂-90 wt% Al₂O₃ support, Ni as active sites, and a strontium promoter, which offers a promising solution. Characterization of the 5NixSr/10Zr+Al catalyst series (x = 0–4 wt%) was conducted using XRD, surface area and porosity analysis, and TPR, TPO, TPD techniques, revealing the stability of metallic Ni derived from the reduction of "moderately interacted NiO-species" under oxidizing-reducing conditions. Incorporating 3 wt% Sr in the 5Ni/10Zr+Al catalyst enhanced reducibility and promoted efficient oxidation of carbon deposits by CO₂. The resulting 5Ni3Sr/10Zr+Al catalyst exhibited additional strong basic sites, leading to ∼82% H₂ yield and effective inhibition of parallel H₂-consuming reactions. Remarkably, the H₂ yield remained stable at ∼79% over a 51-hour time on stream, while process optimization using response surface methodology yielded an optimized H₂ yield of 89% under specific conditions. Experimental validation demonstrated an H₂ yield of 87.4% with excellent stability for a 10-hour time on stream. Overall, the proposed catalyst system demonstrates cost-effectiveness, high performance, and stability, making it a promising candidate for DRM applications.