Multi-wall carbon nanotube-supported palladium-cobalt oxide nanoparticle as efficient catalyst for oxygen reduction reaction

A facile one-step solvothermal approach is adopted to synthesize a multi-wall carbon nanotube-supported palladium-cobalt oxide nanoparticle catalyst (Pd-CoO/MWCNT) as a highly efficient electrocatalyst for oxygen reduction reaction (ORR) in alkaline conditions. In the composite material, Pd-CoO nanoparticles with an average particle size of 6.2 nm are found uniformly anchored on the MWCNTs. MWCNTs form a conductive carbon network with high specific surface area, which favors both mass transport and charge transfer for the electrochemical reaction. The Pd-CoO/MWCNTs exhibit a comparable ORR activity and excellent durability in 0.1 mol/L KOH environment. More significantly, under electrochemical accelerated durability test, the Pd-CoO/MWCNTs can endure at least 14,000 cycles with negligible activity decay. The improved ORR activity and stability of Pd-CoO/MWCNTs demonstrate the effectiveness of introducing transition metal oxide in the development of high-performance non-Pt catalysts for fuel cells and metal-air batteries.