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

Abstract

© 2018, Springer Nature B.V. Preparation, characterization, and electrocatalytic study of the electrodeposited Pt and Pd (e.g., Pt and PtPd) catalysts on titanium dioxide (TiO2) modified reduced graphene oxide (rGO) support for formic acid oxidation were performed. The catalyst composites are labeled as xPt/rGO-TiO2, xPtyPd/rGO-TiO2, and yPd/rGO-TiO2where 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-TiO2. 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-TiO2catalyst 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 6Pt/rGO-TiO2catalyst. According to the experimental data, the Pd and TiO2enhance 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. [Figure not available: see fulltext.].