Vertically Aligned Titanium Nitride Nanorod Arrays as Supports of Platinum-Palladium-Cobalt Catalysts for Thin-Film Proton Exchange Membrane Fuel Cell Electrodes

The degradation of the carbon supports and high platinum (Pt) loading significantly hinder the wide adoption of proton exchange membrane fuel cells. In conventional electrodes, the ionomer binders introduce an undesirable, high oxygen‐transport resistance and cover the catalysts active sites. Herein, an advanced catalytic layer based on vertically aligned titanium nitride nanorod arrays (TiN NRs) is prepared, without additional ionomer or binders in the cathode. After supporting the thin‐film platinum–palladium–cobalt (PtPdCo) catalyst (Pt loading: 66.9 μm cm−2) onto TiN NRs, the ordered electrodes were investigated as the cathode of a single cell without additional ionomer in the catalytic layer. With this electrode architecture, the as‐synthesized electrode performs with a maximum power density of 390.5 mW cm−2 and cathode mass‐specific power density of 5.84 W mgPt−1. The 2000 potential cycles accelerated degradation test shows that the PtPdCo–TiN electrode is more stable than the commercial gas diffusion electrode. Ionomer‐ and carbon‐free thin‐film electrode: An order‐structured electrode based on TiN nanoarrays is proposed. The as‐prepared PtPdCo–TiN electrodes are more stable than the commercial gas diffusion electrode for PtPdCo alloy catalysts and a non‐carbon support. Without binders and with the order structured electrode, the fuels easily access the three‐phase boundary.