Highly efficient electrocatalysts for oxygen reduction reaction: Nitrogen-doped PtNiMo ternary alloys

Abstract

The relatively low efficiency of the reaction of oxygen reduction (ORR) remains among the main obstacles for hydrogen fed proton exchange membrane fuel cells (H-PEMFCs) commercialization. In the present work, PtNiMo ternary alloy catalysts are obtained through reducing by NaBH4 and subsequent thermal annealing in NH3 at 1.0 atm. The as prepared catalysts are physico-chemically (XRD, TEM and XPS) characterized, exhibiting alloy nanostructure. From the electrochemical tests it is found that they exhibit high ORR activity in aqueous solutions saturated with O2 and acidified with HClO4. From the as synthesized catalysts, Pt3Ni3MoN/C shows the highest mass activity (539.41 mA mg−1 Pt); 3.5 times greater than that observed over commercial Pt/C (154.46 mA mg−1 Pt). Moreover, they show very good stability, while their ORR activity is only slightly altered after 5,000 cycles. These highly performing and low cost catalysts could thus open up new possibilities for the commercialization of hydrogen fed PEMFCs. © 2019 Hydrogen Energy Publications LLC