Investigation of Au@Co-B nanoparticles as anode catalyst for direct borohydride fuel cells

The Au@Co-B nano-particles are prepared by chemical reduction and used as anode catalyst in direct borohydride fuel cells (DBFCs). The physical and electrochemical properties of the catalyst are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and fuel cell tests. The physical characterisation demonstrates that the crystalline Au particles are wrapped by amorphous Co-B, and the average size of Au@Co-B particles are about 15 nm. The fuel cell tests prove that the kinetics property of Au@Co-B is improved significantly and material cost reduced obviously compared with pure Au catalyst for DBFC. The maximum power output of 85 mW cm^-2 is achieved at 25°C for this cell without using any ion exchange membranes. This power density performance is also better than some noble metal and bimetallic anode in DBFCs which reported in literatures. And this cell also has a good durability, with no attenuation observed after 80 h of operation.