Platinum Black Coated on Carbon Paper Electrode with PTFE Binder for High-Temperature Proton-Exchange Membrane Fuel Cell (HTPEMFC), CHTPEMFCEPtBCP

Platinum Black coated electrodes are high-performance components specifically designed for environments where standard carbon-supported catalysts (Pt/C) might fail due to corrosion or where extremely high power density is required. Unlike Pt/C, which uses carbon as a scaffold, Platinum Black is composed of pure, finely divided metallic platinum.

In high-temperature PEM fuel cells (HT-PEMFCs), which typically operate between 150°C and 180°C, the combination of Platinum Black and a PTFE (Polytetrafluoroethylene) binder is a classic material choice for the catalyst layer (CL). Unlike low-temperature systems that use Nafion as a binder, HT-PEMFCs rely on phosphoric acid (H3PO4) for proton conduction. The PTFE binder serves as the "scaffold" and "waterproofing" agent that manages this acid.

In HT-PEMFCs, Platinum Black (unsupported Pt nanoparticles) is often preferred over carbon-supported platinum (Pt/C) in specific high-load applications: (1) Corrosion Resistance: At 160°C+ and high potentials, carbon supports can undergo electrochemical oxidation (carbon corrosion). Pt Black eliminates this risk. (2) High Volumetric Activity: It allows for a thinner catalyst layer while maintaining high catalyst loading (often 2–4 mg/cm2), which is necessary because H3PO4 poisons the Pt surface more than Nafion does.

PTFE is the standard binder for HT-PEMFCs due to its extreme thermal stability (melting point ~ 327°C) and chemical inertness. (1) Hydrophobicity & Acid Management: PTFE creates "dry" hydrophobic channels. This is critical to prevent the liquid phosphoric acid from completely "flooding" the catalyst pores, which would block oxygen from reaching the Platinum. (2) Three-Phase Boundary (TPB): It helps establish the site where the reactant gas (Oxygen), the electrolyte (H3PO4), and the catalyst (Pt Black) meet. (3) Structural Integrity: It binds the heavy Pt Black particles together, preventing the electrode from cracking under the thermal expansion cycles of the fuel cell.

Notes: Please try to store the platinum black electrodes in a dry place.

References: 

1. S. H. Kwon, et al. Distribution characteristics of phosphoric acid and PTFE binder on Pt/C surfaces in high-temperature polymer electrolyte membrane fuel cells: Molecular dynamics simulation approach, Int. J. Hydrogen Energy, 2021, 46, 17295-17305.
2. J. O. Park, et al. Role of Binders in High Temperature PEMFC Electrode, J. Electrochem. Soc., 2021, 158, B675.