Pd nanotube electrodes with improved electrocatalytic stability for formic acid electrooxidation

We report Pd nanotube electrodes fabricated by means of electrodeposition method as a function of applied current density. Transmission electron microscopy and scanning electron microscopy images show that the higher applied current density results in the rougher surface structure. From the X-ray diffraction patterns, it is observed that the smaller grain size of the Pd nanotube electrodes may be attributed to the higher applied current density. In the electrochemical data, it is found that the Pd nanotube electrode with the smaller grain size results in much higher electrocatalytic properties for formic acid electrooxidation. The Pd nanotube electrode electrodeposited under the highest applied current density exhibits the improved electrocatalytic stability in comparison with Pd catalyst supported by carbon black (Pd/C, E-TEK, Co.).