Interstitial Carbon-Doped PdMo Bimetallene for High-Performance Oxygen Reduction Reaction

Metallenes have been identified as one of the most promising electrocatalysts for fuel cells. However, non-noble metal species in metallenes would suffer from severe oxidation/dissolution during catalysis, causing vigorous activity decay. Here, we report that carbon doping can effectively enhance the catalytic activity and stability of metallenes for the oxygen reduction reaction (ORR). Taking PdMo bimetallene as an example, PdMo bimetallene toward ORR can exhibit ∼2 times the enhancement in mass and specific activities via carbon doping and retain ∼3 times more Mo than undoped bimetallene after 30 000 cycles. XPS and theoretical simulations reveal that the covalent bonds formed by the hybridization of Mo and C orbitals not only stabilize Mo species and inhibit the oxidation of Mo but also optimize the oxygen binding and thus improve the catalytic activity. The study sheds new light on the commercialization of metallene electrocatalysts in fuel cells.