Assembling molybdenum-doped platinum clusters into a coral-like nanostructure for highly enhanced oxygen reduction

Regulating the electronic and geometric structures of electrocatalysts is an effective strategy to boost their catalytic properties. Herein, a coral-like nanostructure is assembled with Mo-doped Pt clusters to form a highly active catalyst toward the oxygen reduction reaction (ORR). The advantages of a Mo-doped porous skeleton, grain boundaries, and MoOx species on the Pt cluster surfaces synergistically boost the electrocatalytic performance. This unique architecture delivers 3.5- and 2.8-fold higher mass and specific activities, respectively, than commercial Pt/C. Density functional theory calculations reveal that the Mo-doped Pt clusters have an optimized Pt-O bond length of 2.110 angstrom, which weakens the adsorption energy of the intermediate O* to yield great ORR activity. Moreover, the catalyst shows a decay in the half-wave potential of only 8 mV after 10,000 cycles of accelerated durability testing. The high stability arises from the increased dissociation energy of Pt atoms and the stable architecture of the coral-like structure of clusters.