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Effective water management is crucial for the optimal operation of low‐temperature polymer electrolyte membrane fuel cells (PEMFCs). Excessive liquid water production can cause flooding in the gas diffusion electrodes and flow channels, limiting mass transfer and reducing PEMFC performance. To tackle this issue, a nature‐inspired chemical engineering (NICE) approach has been adopted that takes cues from the integument structure of desert‐dwelling lizards for passive water transport. By incorporating engraved, capillary microchannels into conventional flow fields, PEMFC performance improves significantly, including a 15% increase in maximum power density for a 25 cm2 cell and 13% for a 100 cm2 cell. Electro‐thermal maps of the lizard‐inspired flow field demonstrate a more uniform spatial distribution of current density and temperature than the conventional design. Neutron radiography provides evidence that capillary microchannels in the lizard‐inspired flow field facilitate the efficient transport and removal of generated liquid water, thereby preventing blockages in the reactant channels. These findings present a universally applicable and highly efficient water management strategy for PEMFCs, with the potential for widespread practical implementation for other electrochemical devices. [ABSTRACT FROM AUTHOR]

Abstract: Pt/C/MnO2 hybrid catalysts were prepared by a wet chemical method. Pt/C electrocatalysts were treated with manganese sulfate monohydrate (MnSO4·H2O) and sodium persulfate (Na2S2O8) to produce MnO2. The presence of MnO2 was confirmed by FTIR spectroscopy. Rotating ring–disk electrode (RRDE) experiments were performed on electrodes prepared using the hybrid electrocatalysts to estimate the amount of hydrogen peroxide (H2O2) formed during the oxygen reduction reaction (ORR) as a function of MnO2 content. Pt/C/MnO2 (5% by weight of MnO2) hybrid electrocatalysts produced 50% less hydrogen peroxide than the baseline Pt/C electrocatalyst. The hybrid electrocatalysts were used to prepare membrane electrode assemblies that were tested at 90°C and 50% RH at open circuit with pure hydrogen as fuel and air as the oxidant. The fluoride ion concentration was measured using an ion selective electrode. The concentration of F− in the anode condensate over 24h was found to be reduced by a factor of 3–4 when Pt/C/MnO2 replaced Pt/C as the catalyst. Through cyclic voltammetry and RRDE kinetic studies, the lower ORR activity of the acid treated hybrid electrocatalysts was attributed to catalyst treatment with acid during MnO2 introduction. The activity of the hybrid catalyst was improved by switching to a water-based synthesis. [Copyright &y& Elsevier]