Origin of hetero-nuclear Au-Co dual atoms for efficient acidic oxygen reduction

The atomically dispersed dual metal atom catalysts exhibit significant promise for the electrochemical energy conversion technologies. Herein, the hetero-nuclear precious-non-precious (Au-Co) dual atoms have been synthesized and subsequently applied for the acidic oxygen reduction reaction (ORR). The (Au-Co) dual atoms exhibit an outstanding activity with half-wave potential (E) of 0.82 V in 0.1 M HClO. Additionally, the proton exchange membrane fuel cell (PEMFC) analysis reveals a peak power density of 360 mW cm under H/air condition. Co-NC with axial Au atom moieties act as the active sites of the (Au-Co) dual atoms towards ORR. Further, *OH adsorbed on the Co atom induces a coordinated change in the adjacent Au atom symmetry, which leads the anti-bond spin orbitals to a low energy level, thus, further improving ORR performance. The development of (Au-Co) dual atoms via the regulation of D-orbitals symmetry provides an encouraging way to design highly efficient (electro)catalysts.