We　report　a　facile　but　effective　approach　to　construct　a　highly　dispersed　diatomic　catalyst.　A　carbon-embedded　diatomic　Ni2　catalyst　was　synthesized　from　carbon　black,　polyaniline　and　nickel(ii)　salts.　The　resulting　catalyst　exhibits　excellent　activity　for　the　CO2　reduction　reaction　(CO2RR)　at　low　Ni　content　with　a　faradaic　efficiency　of　CO　over　95%　in　the　potential　range　from　-0.6　V　to　-1.0　V　vs.　reversible　hydrogen　electrode　(RHE).　A　high　specific　current　density　of　37.2　A　mg-1　Ni　was　recorded　at　-1.1　V,　among　the　highest　reported　values　for　Ni-based　electrocatalysts.　This　journal　is　©　The　Royal　Society　of　Chemistry.