Ni-based core-shell structured catalysts for efficient conversion of CH₄ to H₂: A review

Methane (CH₄) serves as a primary constituent of natural gas and a potent greenhouse gas. Catalytic conversion of CH₄ into H₂ presents a promising avenue for mitigating CO₂ emissions from direct CH₄ combustion, while also facilitating the transition towards cleaner energy sources. Substantial efforts have been dedicated to enhancing the efficiency of methane conversion and the selectivity for hydrogen in catalyst design. Among these endeavors, core-shell structured Ni-based catalysts have emerged as highly advantageous catalysts for CH₄ conversion, with a multitude of benefits including high catalytic activity, coking resistance, and longtime stability. In this review, we provide an overview of Ni-based core-shell catalysts. Furthermore, the synthesis methods of core-shell Ni-based catalysts are explored. We then delve into the myriad advantages these core-shell structured catalysts confer upon methane conversion, specifically emphasizing their remarkable stability and resistance to sintering, and CO₂ activation capacity in dry reforming of methane. Moreover, this review comprehensively outlines the versatile applications of Ni-based core-shell structured catalysts in processes such as steam reforming of methane (SRM), dry reforming of methane (DRM), partial oxidation of methane (POM), and catalytic methane decomposition (CMD) for H₂ production. Additionally, we delve into the recent advancements in the field of computational chemistry, with a particular focus on density functional theory (DFT) and machine learning (ML). These techniques play pivotal roles in screening Ni-based catalysts and offer insights into the intricate reaction mechanisms underlying methane conversion. Finally, we summarize the key findings of this review and provide forward-looking perspectives. This comprehensive review serves as a valuable reference in the realm of hydrogen production from methane on core-shell structured catalysts, fostering a deeper understanding of this promising area.