Superior Formic Acid Oxidation Using Carbon Nanotube-Supported Palladium Catalysts

Abstract

In the work presented here, we report a palladium-decorated carbon nanotube catalyst that shows enhanced activity for formic acid electrooxidation. At 0.3 V vs RHE, the palladium-decorated carbon nanotube catalyst showed a current of 0.18 mA cm–2, whereas a standard commercial palladium black catalyst only showed a current of 0.082 mA cm–2. Also, during a 12 h chronoamperogram at 0.3 V vs RHE, the palladium-decorated carbon nanotube catalyst showed a factor of 3.5 improvement at the end of 12 h. The current was also much more stable for the palladium-decorated carbon nanotubes. During the last 8.5 h, the palladium-decorated carbon nanotubes show a current loss of 36%, whereas the standard palladium black catalyst showed a current loss of nearly 90%. Lastly, we report that the palladium-decorated carbon nanotubes showed better current stability under potential cycling. After 300 cycles in 12 M HCOOH from 0.02 to 1.45 V vs RHE, the palladium-decorated carbon nanotubes showed only a 33% current loss when measured at 0.3 V vs RHE. However, the standard palladium showed a decay of 60% when also measured at 0.3 V vs RHE.