Carbon-embedded Ni catalysts for highly efficient CO₂ methanation

The design and preparation of highly active and stable Ni-based catalysts has attracted extensive attention. In this study, a series of embedded Ni@C catalysts were synthesized by a facile sol-gel method. After reduction at 400 °C, the optimized Ni@C-400 catalyst showed excellent performance in CO₂ methanation at a low temperature of 300 °C, with a CO₂ conversion of 74.3 % and good stability for 70 h. The characterization results indicated that after reduction treatment, the carbon species in the precursor were transformed into graphite carbon with more disorder defects. This structure facilitated the anchoring effect of the nickel components in the Ni@C catalyst, thereby forming a distinctive embedded structure that ensured the preservation of the nickel active phase in the catalyst following prolonged reaction. Therefore, the Ni@C catalyst prevented severe sintering and loss of loaded nickel. In addition, the interaction between Ni and C facilitated charge transfer, enhancing the CO₂ activation.