Multiparameter Performance Mapping and Net-Power Assessment of Oxygen-Enriched PEMFCs toward Pressure Swing Adsorption Integration

Oxygen-enriched air (OEA) can substantially enhance proton exchange membrane fuel cell (PEMFC) performance, but conventional oxygen supply remains costly and complex. Miniaturized pressure swing adsorption (PSA) offers a promising route to on-demand OEA generation, yet integration feasibility depends on PEMFC responses across the OEA purity range accessible to PSA. An 84-run D-optimal design was conducted over 21–100% OEA purity to map PEMFC performance across an operating space spanning OEA purity, pressure, inlet relative humidity (RH), temperature, and cathode stoichiometric ratio (CSR). Electrochemical impedance spectroscopy and distribution-of-relaxation-times analysis were combined with quadratic response surface modeling to capture nonlinear interactions and high-performance operating windows. Oxygen enrichment reduced charge-transfer and mass-transfer resistances by approximately 71% and 92%, respectively, at 1.6 A/cm2, while marginal gains diminished around ∼70% OEA purity and above. Parameter importance followed OEA purity > pressure > RH > temperature ≈ CSR. Response surface analysis revealed load-dependent shifts in RH windows and reduced CSR sensitivity, with less than 2% power loss when CSR decreased from 2.5 to 1.3 under pure oxygen at 0.55 V. A preliminary assessment based on literature PSA data indicated cathode-supply-adjusted net-power gains of 72–79% for 94.1% OEA at low CSR. Although 74.9% OEA yielded slightly lower net power, it required approximately one-third less adsorbent for the same oxygen demand, providing a favorable trade-off between net power and compactness. These results provide quantitative guidance for OEA purity selection, parameter matching, and compact oxygen-supply design for PEMFC applications.