Currently, hydrogen is recognized as the best alternative for fossil fuels because of its sustainable nature and environmentally friendly processing. In this study, hydrogen dissociation reaction is studied theoretically on the transition metal doped carbon nitride (C2N) surface through single atom catalysis. Each TMs@C2N complex is evaluated to obtain the most stable spin state for catalytic reaction. In addition, electronic properties (natural bond orbital NBO & frontier molecular orbital FMO) of the most stable spin state complex are further explored. During dissociation, hydrogen is primarily adsorbed on metal doped C2N surface and then dissociated heterolytically between metal and nitrogen atom of C2N surface. Results revealed that theFe@C2N surface is the most suitable catalyst for H2 dissociation reaction with activation barrier of 0.36 eV compared with Ni@C2N (0.40 eV) and Co@C2N (0.45 eV) complexes. The activation barrier for H2 dissociation reaction is quite low in case of Fe@C2N surface, which is comparatively better than already reported noble metal catalysts.