Synthesis and Characterization of Platinum on Carbon Nanoparticles Selectively Coated with Titanium Nitride (TiN)

Abstract

Here we propose a novel way to prevent the insidious effect of carbon corrosion in a Proton Exchange Membrane Fuel Cell (PEMFC) by depositing a corrosion-resistant layer (~1.5 nm thick) of Titanium Nitride (TiN) on the carbon substrate of platinum on carbon (Pt/C) catalyst (in powder state), leaving the Pt catalyst centers uncoated and accessible for reagents reactions (oxygen O2 and H+ protons). The deposition was carried out at 150°C with a Hollow-Cathode Plasma-Assisted Atomic Layer Deposition (HCPA-ALD) using Tetrakis(dimethylamino)titanium (IV) (TDMAT) as the metal precursor in Ar/N2 plasma, from which nitrogen was used as co-reactant. Additionally, Transmission Electron Microscopy (TEM) characterization allowed us to prove the successful formation of a homogenous coating on these nanoparticles and electrochemical characterization performed with a Rotating Disc Electrode (RDE) further confirmed the activity and effectiveness of our designed catalyst. Preliminary results have shown that highly conformal TiN can be successfully grown onto Pt/C nanoparticles by using HCPA-ALD with a custom-made agitator mechanism.