The studies of performance of the Au electrode modified by Zn as the anode electrocatalyst of direct borohydride fuel cell

The carbon supported Au-base electrocatalysts (Au(1−x)Znx/C, 0 ≤ x < 1) modified by Zn were synthesized by reverse microemulsion method and employed as anode electrocatalysts of direct borohydride fuel cell (DBFC). The physical and electrochemical properties were investigated by energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronopotentiometry and fuel cell test. The results showed that the morphologies of Au(1−x)Znx nanoparticles all were uniformly spherical no matter what Zn content changed, and the average particle size of Au(1−x)Znx bimetallics varied from 3 to 6 nm. The electrochemical measurements revealed that the Au(1−x)Znx/C electrocatalysts showed no activity toward the NaBH4 hydrolysis reaction and obviously improved the catalytic activity of borohydride oxidation. Compared with Au/C anode electrocatalyst, the stability of DBFC using the Au0.65Zn0.35/C as anode electrocatalyst was apparently improved, and the maximum power density of 39.5 mW cm−2 was obtained at 20 °C.

► The Au(1−x)Znx/C catalysts as the anode electrocatalysts of DBFC were synthesized. ► The average particle size of Au(1−x)Znx bimetallics varied from 3 to 6 nm. ► The Au(1−x)Znx/C can apparently improve the catalytic activity of BH4− oxidation. ► The Au(1−x)Znx/C catalysts show no activity toward the NaBH4 hydrolysis reaction. ► The maximum power density of 39.5 mW cm−2 was obtained at 20 °C.