Microfluidic synthesis of platinum nanoparticles supported on reduced graphene oxide, titanium dioxide, and carbon for PEM fuel cells

Abstract

Platinum (Pt) nanoparticles on various supports, such as commercial carbon powder, titanium dioxide (TiO2), and reduced graphene oxide (rGO), were synthesized using a continuous flow microfluidic system. First, the support materials were separately synthesized using the sonochemical technique followed by the loading of Pt. The Pt nanoparticles on different supports were characterized using Brunauer–Emmett–Teller (BET) for surface area and porosity analysis; X-ray diffraction (XRD) for structural confirmation; Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) for surface composition; and transmission electron microscopy (TEM) for morphological investigation. Further, polymer electrolyte membrane (PEM) fuel cells were fabricated using the Pt nanoparticles on different supports, and cyclic voltammetry (CV), linear sweep voltammetry (LSV), and power density were performed. Among the three electrocatalysts, Pt/rGO showed the highest electrochemical performance. Pt/rGO showed higher specific activity (119 mA/cm2), mass activity (238 mA/mg), current density (1274 mA/cm2), and power density (497 mW/cm2). We also determined the mass activity and specific activity of the electrocatalysts based on the electrochemical data. This work shows the potential of the microfluidic system to continuously synthesize the technologically important nanomaterials and their application for energy conversion devices.