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Dry methane reforming (DRM) is a promising process for converting CO₂ and CH₄ into syngas to mitigate greenhouse gas emissions. However, catalyst deactivation caused by active metal sintering and carbon poisoning presents significant challenges for practical applications of DRM. To address this, researchers have developed robust metal oxide composite catalysts with strong metal-support interaction (SMSI) properties to enable extended operation with minimal activity loss. Effective catalyst pelletization is also critical to prevent reactor and equipment failure from powder blockages, pressure drop, and surface-active site blockage. Therefore, optimizing catalyst pellets with high conversion efficiency is essential to enhance reactor stability and catalyst lifespan.

In this study, a catalyst bead of Ni/Mg/Ce metal oxide composite with a hierarchical porous structure was developed. The as-prepared catalysts were applied for the DRM reaction by adjusting the support component ratio. The optimized catalyst was tested for stability at 750℃ for 110 hours to evaluate its reaction stability and pressure drop mitigation.

The physicochemical characteristics of the catalyst were analyzed using H₂-TPR, XPS, HR-TEM with EDS, and XRD to identify the formation of a Ni/Mg/Ce solid solution, inducing SMSI with well-distributed Ni particles under 20 nm and sufficient surface oxygen for enhanced carbon oxidation. The physical and carbon analysis of the catalyst was performed using FE-SEM with EDS, TGA, and Raman, revealing the distinct carbon generation and unique catalyst surface reconstruction behavior of the hierarchical porous structure.

The optimized Ni/Mg/Ce catalyst with a hierarchical porous structure demonstrated enhanced reaction stability and pressure drop mitigation, supported by its free volume and dense-shell structure. The findings suggest potential for the optimized catalyst in industrial-scale DRM and other high-temperature reactions.