Catalytic investigation of PtPd and titanium oxide-loaded reduced graphene oxide for enhanced formic acid electrooxidation

Preparation, characterization, and electrocatalytic study of the electrodeposited Pt and Pd (e.g., Pt and PtPd) catalysts on titanium dioxide (TiO 2 ) modified reduced graphene oxide (rGO) support for formic acid oxidation were performed. The catalyst composites are labeled as x Pt/rGO-TiO 2 , x Pt y Pd/rGO-TiO 2 , and y Pd/rGO-TiO 2 where x and y are cycle numbers of metal electrodeposition ( x and y = 2–6). The characterizations of the catalysts were performed by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Small and dispersed metal nanoparticles are obtained on rGO-TiO 2 . The catalytic performances for formic acid oxidation were measured by cyclic voltammetry (CV) and chronoamperometry (CA). The electrocatalytic results reveal that the bimetallic 4Pt2Pd/rGO-TiO 2 catalyst facilitates formic acid oxidations at the lowest potentials and generates the highest oxidation currents and also improves the highest CO oxidation compared to the monometallic 6 Pt/rGO-TiO 2 catalyst. According to the experimental data, the Pd and TiO 2 enhance the electrocatalytic activity of the catalysts towards the formic acid oxidation; the improved catalytic performance of the prepared catalysts strongly relates to the high electrochemically active surface area (ECSA) investigated. Graphical abstract TEM image of xPtyPd/rGO-TiO 2 and its CV towards oxidation