Speeding up biphasic reactions with surface nanodroplets

The kinetics of a model biphasic reaction at the interface of surface nanodroplets is quantitatively studied. The droplet reaction time scales with ∼Pe−2/3 of the reactant flow. Enhanced mass transport contributes to accelerated kinetics.

Experimental Studies of Effect of Land Width in PEM Fuel Cells with Serpentine Flow Field and Carbon Cloth

Flow field plays an important role in the performance of proton exchange membrane (PEM) fuel cells, such as transporting reactants and removing water products. Therefore, the performance of a PEM fuel cell can be improved by optimizing the flow field dimensions and designs. In this work, single serpentine flow fields with four different land widths are used in PEM fuel cells to study the effects of the land width. The gas diffusion layers are made of carbon cloth. Since different land widths may be most suitable for different reactant flow rates, three different inlet flow rates are studied for all the flow fields with four different land widths. The effects of land width and inlet flow rate on fuel cell performance are studied based on the polarization curves and power densities. Without considering the pumping power, the cell performance always increases with the decrease in the land width and the increase in the inlet flow rates. However, when taking into consideration the pumping power, the net power density reaches the maximum at different combinations of land widths and reactant flow rates at different cell potentials.

Characterization of Solid Oxide Fuel Cells with LSCF-SDC Composite Cathodes

This paper reports the study of an anode-supported SOFC cell containing an LSCF-SDC composite cathode. The SOFC cell was tested at different temperatures and reactant flow rates. After testing, the cell was sectioned and characterized using SEM/EDS. Such analysis indicated that no structural damage and no significant interdiffusion of elements among the layers occurred. The measured electrochemical performance data at different temperatures indicate an Arrhenius behavior or temperature activated processes. The low-porosity anode functional layer appears to be very sensitive to low hydrogen contents. The electrochemical performance is also affected by changing air flow rates.