Tailoring the metallic composition of Pd, Pt, and Au containing novel trimetallic catalysts to achieve enhanced formic acid electrooxidation activity

Herein, carbon-supported Pt, PtAu, and PdPtAu catalysts were synthesized via the NaBH4 reduction method. Electrocatalytic activity of the catalysts for formic acid electrooxidation was investigated by using cyclic voltammetry (CV), chronoamperometry (CA), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). X-ray diffraction (XRD), N2 adsorption-desorption, and temperature programmed reduction (TPR) techniques were used for the characterization of the synthesized catalysts. The enhanced electrocatalytic activity was observed for PtAu catalysts by the addition of Pd which can be explained through the synergistic effect between Pd and Au. Pd75Pt5Au20/CNT exhibited the highest catalytic activity of 36.8 mAcm−2, and similar results were also obtained for other trimetallic catalysts containing low amount of Pt. These results lead us to conclude that low Pt content provides higher electrocatalytic activity and CO poisoning tolerance. To our knowledge, the significance of Pd ratio optimization for PdPtAu catalyst system was reported for the first time in the literature.