Nickel　is　a　crucial　catalyst　for　its　excellent　performance　in　active　carbon　atom-related　catalysis　such　as　hydrocarbon　steam　reforming　and　1D　carbon　nanostructures　preparation.　The　carbon　diffusion　activity　in　Ni　is　of　critical　importance　in　understanding　the　catalytic　behavior　and　thereby　the　performance　optimization.　However,　the　carbonization　process　is　still　vague　because　of　the　hardly　identified　intermediates.　In　this　paper,　the　metastable　intermediates　of　nickel　carbonization　process　are　successfully　stabilized　by　taking　advantage　of　the　epitaxial　growth　to　elevate　the　structure　transformation　energy　barrier.　X-ray　diffraction,　high-resolution　transmission　electron　microscopy,　and　synchrotron　X-ray　absorption　near　edge　structure　data　evidence　the　face-centered　cubic　(fcc)-NixC　nature　of　the　intermediates　and　thus　an　fcc-NixC-intermediated　nickel　carbonization　process　from　fcc-Ni　to　hexagonal　close-packed　(hcp)-Ni3C　is　revealed,　which　is　also　confirmed　by　the　Vienna　ab　initio　simulation　package　calculation　from　the　viewpoint　of　energy　evolution.　To　the　best　of　the　knowledge,　it　is　the　first　time　to　report　the　identification　of　the　fcc-NixC.　More　importantly,　the　introduction　of　Au　is　found　promoted　the　catalytic　growth　of　graphitic　carbon　using　either　oleylamine　or　C2H4　as　carbon　resource.　The　Au@Ni-based　hybrid　catalysts　exhibit　lower　reaction　temperature　and　much　higher　carbon　output　than　pure　Ni.