Non-Carbon-Supported, Pt-Based Catalysts with Applications in the Electrochemical Hydrogen Pump/Compressor (EHP/C)

In this study, platinum (Pt) nanocatalysts were synthesized via a sol-gel method over the non-stoichiometric, Magnéli phase titanium oxides (TinO2n−1) at varying Pt loadings (10–40 wt.%). Their structural and morphological properties were characterized, and after preliminary electrochemical screening, the catalysts were integrated into commercially available gas diffusion electrodes (GDEs) with a three-layer structure to enhance mass transport and catalyst utilization. Membrane electrode assemblies (MEAs) were fabricated using a Nafion® 117 polymer membrane and tested in a laboratory PEM cell under controlled conditions. The electrochemical activity toward the hydrogen reduction reaction (HRR) was evaluated at room temperature and at elevated temperatures to determine the catalytic efficiency and stability. The optimal Pt loading was determined to be 30 wt.%, achieving a current density of approximately 0.12 A cm−2 at 0.25 V, demonstrating a balance between catalyst efficiency and material utilization. The chronoamperometry tests showed minimal degradation over prolonged operation, suggesting that the catalysts were durable. These findings highlight the potential of Pt-based catalysts supported on Magnéli phase titanium oxides (TinO2n−1) for efficient HRRs in electrochemical hydrogen pumps/compressors, offering a promising approach for improving hydrogen compression efficiency and advancing sustainable energy technologies.