Polycarbazole as an efficient promoter for electrocatalytic oxidation of formic acid on Pt and Pt–Ru nanoparticles

Electrocatalytic activities of the monometallic Pt and bimetallic Pt–Ru nanoparticles dispersed onto polycarbazole (PCZ) films obtained by the electropolymerization on glassy carbon electrode (GC) (i.e., Pt/PCZ/GC, Pt–Ru/PCZ/GC) towards formic acid oxidation have been investigated using cyclic voltammetry and chronoamperometry methods. As-formed electrodes are characterized by SEM, EDX and electrochemical analysis. Relative to Pt and Pt–Ru deposited on the bare GC (i.e., Pt/GC and Pt–Ru/GC), Pt/PCZ/GC and Pt–Ru/PCZ/GC, respectively, exhibit higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electrooxidation. The enhanced performance is proposed to come from the synergetic effect between metal nanoparticles (Pt, Pt–Ru) and PCZ. At the same time, the results of the stripping voltammograms of CO show that PCZ can weaken largely the adsorption strength of CO on catalysts and can make CO oxidation easier under lower potential, implying further that PCZ can be used as an efficient promoter for electrocatalytic oxidation of formic acid on Pt/PCZ and Pt–Ru/PCZ catalysts.