PdCu Bimetallene for Enhanced Oxygen Reduction Electrocatalysis.

Engineering two-dimensional (2D) metallic nanomaterials has attracted numerous research interests for oxygen reduction reaction (ORR) due to their highly exposed unsaturated metal atoms and excellent physicochemical properties. Herein, we report a CO-confined growth strategy for the synthesis of 2D PdCu bimetallene with several atomic layers for ORR. The incorporation of Cu into Pd metallene can generate strain effect and change the electronic structure, weakening the interaction between Pd and CO and suppressing the adsorption of CO. Therefore, the synthesized PdCu bimetallene exhibits remarkable catalytic performance for alkaline ORR, with mass and specific activities of 0.82 A mg and 1.01 mA cm, which are 5.1 and 3.7 times those for Pt/C, respectively. Meanwhile, the PdCu bimetallene shows no decrease in ORR activity after 5000 cycles. This work highlights the design of ultrathin bimetallic 2D nanomaterials for efficient ORR electrocatalysis.