Advances in supported Nickel single-atom catalysts for CO2 Valorization: Synthesis, applications and stability enhancement

Recent advancements in supported nickel single-atom catalysts (Ni-SACs) have demonstrated remarkable potential in the catalytic conversion and valorization of carbon dioxide (CO₂). This review systematically evaluates the importance, historical development, and current synthesis strategies of Ni-SACs as efficient heterogeneous catalysts. Various synthesis methods, including hydrothermal techniques, wetness impregnation, atomic layer deposition, pyrolysis, atom trapping, and co-precipitation, are comprehensively discussed. The role of different support materials, such as single oxides, composite oxides, and non-oxide supports, in enhancing catalytic performance and stability is analysed. Additionally, the review critically assesses the applications of Ni-SACs in thermocatalysis, photocatalysis, and electrocatalysis CO₂ conversion processes. Key strategies to improve the stability and durability of Ni-SACs, particularly through tailored anchoring sites and optimized metal-support interactions, are highlighted. Finally, this review outlines the existing challenges and proposes future research directions, aiming to advance the field of catalysis towards more sustainable CO₂ utilization technologies.