Representative non-noble metal SACs are supported on carbon materials by top-down atom-trapping strategy. (A) Synthesis of Ni SACs from Ni NPs [105]. Copyright©2018, John Wiley and Sons. (B) Synthesis of Cu SACs from Cu₂O with atom-trapping and reduction. Reproduced with permission from ref. [107]. Copyright©2019, Springer Nature. (C) Synthesis of Co SACs from CoCl₂ with atom-trapping. Reproduced with permission from ref. [109]. Copyright©2020, Springer Nature.