Photocatalytically Generated Trimetallic (Pt-Pd-Au/C-TiO₂) Nanocomposite Electrocatalyst

Abstract

Facile photochemical synthesis of trimetallic Pt‑Pd-Au nanoclusters supported on carbon-TiO2 (90:10 mass%) supports, is described. Heterogeneous photocatalysis was used for sequential metal photodeposition which was sustained by the photoactivity under bandgap irradiation of the TiO2 substrate component. This new-generation electrocatalyst was characterized by high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron microscopy, and cyclic voltammetry. Its electroactivity for the oxygen reduction reaction (ORR) and durability, assessed by hydrodynamic voltammetry and galvanostatic polarization probes respectively, were compared with the respective bimetallic (Pt-Pd, Pt-Au and Pd-Au) parent materials prepared by an identical synthetic procedure. Fine tuning of the amount and Pt:Pd ratio afforded superior electrocatalytic activity for the ORR, and the Au component of the trimetallic composition enhanced its stability/durability against carbon corrosion.