Ni-Cd carbon nanofibers as an effective catalyst for urea fuel cell

One of the main challenges facing the development of urea fuel cells is the low catalytic activity of the anode. Ni decorated carbon nano-fiber is a promising anode catalyst in urea fuel cells. In this study, we have investigated the effect of Cd doping of Ni decorated carbon nano-fiber on catalytic activity for urea oxidation. The catalyst was prepared by heat treatment of electrospun nano-fibers containing different percentages of Ni and Cd acetates in poly(vinyl alcohol) under an inert atmosphere at 850 °C. The initial percentages of the Cd acetate to Ni acetate in the polymer solution was set at 5, 10, 30, 50 and 70 wt.%. The introduction of Cd significantly improved the electro-catalytic activity for urea oxidation. The sample that was prepared with initial 50 wt.% Cd acetate showed the best activity for urea oxidation activity using different urea concentrations, 0.33 M–3 M. The introduction of Cd improved both the quality and the number of active sites for the urea oxidation as seen from the shift of the anodic peak potential and anodic peak current density, respectively.