Co Nanocluster Strain-Engineered by Atomic Ru for Efficient and Stable Oxygen Reduction Catalysis

Abstract Sluggish kinetics and high Pt dependence of oxygen reduction reaction (ORR) are the primary factors hindering the large-scale commercialization of low temperature fuel cells. Herein, metallic Co is strain-engineered by atomic Ru to boost the ORR activity due to that the barrier of the ORR intermediate absorption energy can be decreased and a preference to a 4 electron ORR pathway can be achieved according to the theoretical calculation. As a result, half wave potential of the Ru adjusted Co catalyst encapsulated with nitrogen-doped carbon (a-Ru@Co/CN) is high to 0.908 V vs. RHE, 58 mV higher than that of commercial Pt/C, with only 1.33 wt% Ru doped. By considering the excellent stability, durability and alcohol tolerance, a-Ru@Co/CN is equipped in direct methanol/isopropanol fuel cells as cathode catalyst. Fuel cell performance can be enhanced by 60% and 138% with methanol and isopropanol as fuel respectively, compared with Pt/C, demonstrating the application potential in practical fuel cell devices.