Atomically Precise Silver Nanocluster Riveted by Uneven Charged Traps toward Enhancing Electrocatalytic Activity for the Oxygen Reduction Reaction.

Abstract

Metal nanoclusters (MNCs) possessed promising potentials for catalytic applications but were hindered by the intrinsic charge-carrier mobility and the exposure of active sites. To this point, our work developed the uneven charged traps strategy to realize the homogeneous dispersion and immobilization of atomically precise silver nanoclusters (Ag6) and obtained an Ag cluster-based oxygen reduction reaction (ORR) electrocatalyst with enhanced performance. As expected, the uneven charged traps derived by graphitized nitrogen-doped carbon (NDC) extended the effective catalytic active area, tuned the electrical environment, and facilitated the binding between ORR intermediates and the active sites. Compared with pure Ag6 nanoclusters, Ag6@NDC possessed nearly 160 times higher electrochemical surface area (ECSA) and dramatically decreased electrochemical impedance spectroscopy (EIS). In alkaline media, the overall catalytic performance of Ag6@NDC with only 3.64 wt % Ag was even superior to commercial 20 wt % Pt/C. This work not only offered a successful showcase to enhance the catalytic performance of atomically precise MNCs but also provided highly efficient alternatives for both electrocatalytic applications and mechanism studies.