Abstract By means of density functional theory (DFT) computations, the CO/O 2 adsorption and CO oxidation pathways on the biatom catalyst, namely the heteronuclear Fe 1 Cu 1 @C 2 N, in comparison with its homonuclear counterparts Fe 2 @C 2 N and Cu 2 @C 2 N are systemically investigated. The reactions of O 2 dissociation and CO oxidization with preadsorbed CO or O 2 are comparably studied. The computations find that the heteronuclear species Fe 1 Cu 1 @C 2 N possesses high stabilities and is feasible to be synthesized experimentally. More importantly, the heteronuclear Fe 1 Cu 1 @C 2 N catalyst has even better catalytic activity toward CO oxidation than its homonuclear counterparts, especially, without suffering the CO‐poisoning problem. Considering the myriad of unexplored heteronuclear dimers that can be potentially anchored at appropriate supports, this work opens a new avenue and provides a useful guideline for further developing bimetal‐based nanocatalysts.