Cooperative Pd@CoNi/rG catalyst for highly efficient and stable electrocatalytic methanol and ethanol oxidations

Methanol and ethanol are liquid carriers of hydrogen, convenient and safe to store and transport, particularly of interest as mobile and marine fuels. These can be directly fed into a fuel cell to impart clean energy efficiently, only if their conversion can be cost-effectively catalyzed. In this regard, a cooperative catalyst is developed with atomic Pd species, in the form of single atoms and nanoclusters, dispersed over non-noble bi-metallic CoNi alloy nanoparticles, further supported on reduced graphene oxide (rG) (Pd@CoNi/rG). The catalyst demonstrates a methanol (ethanol) oxidation, MOR (EOR), mass activity (MA) of 1.730 (3.917) A mg −1 Pd (or Pt) , 4.55 (60.26) times greater than that of the commercial 20 wt% Pt/C and 8.65 (20.61) times higher than that of the commercial 20 wt% Pd/C, respectively. More importantly, the catalyst shows excellent stability, maintaining 83.7% (93.7%) of the initial performance after chronoamperometry (CA) for 50000 s in a solution of 1 M KOH + 1 M CH 3 OH (CH 3 CH 2 OH). It significantly out-performs other mono-/bi- metallic counterparts, e.g., Co/rG, Ni/rG, Pd/rG, CoNi/rG, Pd@Co/rG and Pd@Ni/rG, due to its unique cooperative nanostructure with synergistic effects of the different metal (Pd, Co and Ni)-related species.