Modification of various carbons with various metal oxides and noble metal compositions as electrocatalysts for ethanol oxidation

Abstract

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. The modification of various carbons with various metal oxides and noble metal composites was performed to prepare electrocatalysts, and the catalysts were further investigated for ethanol electro-oxidation. The catalyst activity and stability were studied by cyclic voltammetry (CV) and chronoamperometry (CA), respectively. First, various metal oxides (e.g., TiO2, CeO2 and MnO2) were prepared on a graphene oxide (GO) support. Pt on TiO2 with a GO support (Pt/TiO2-GO) provided a higher current density and long-term stability than the other catalysts. Second, TiO2 was prepared on various carbons (e.g., graphite (G), graphite oxide (GTO), GO and polydopamine (PDA)-modified GO (PDA-GO)), and the corresponding electrocatalytic activities were determined. Pt/TiO2-PDA-GO showed the highest activity and stability for oxidation. Consequently, TiO2-PDA-GO was chosen as a support for further studies on the optimal composition of bimetallic catalysts (xPtyPd/TiO2-PDA-GO). 4Pt2Pd/TiO2-PDA-GO showed the highest performance for ethanol oxidation. The prepared M/TiO2-C catalysts were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The results showed that the dispersed nanoparticles were loaded on the modified carbon supports. From electrochemical measurements, the prepared electrocatalysts showed improved electrocatalytic activities in terms of low onset potential and high current density and stability.