Mechanism of the Hydrogen Gas Diffusion Electrode

Abstract

Equations were formulated for the electrolyte film mechanism, in which H2 diffuses through a film of electrolyte covering the surface of the pores in the electrode. The polarization characteristics at high and low currents were obtained analytically. The equations were solved numerically on a computer using data for H2 on Ni with an NaOH electrolyte for various values of the surface roughness, pore radius and length, temperature, concentration of electrolyte, and film thickness. A similar computer solution was made of Justi's equations for the surface diffusion mechanism, and the results of the two calculations were compared. The results show that the electrolyte film mechanism has a maximum current 300 times larger, and a slope of the polarization curve at low currents, which is 45 times less than that for the surface diffusion mechanism.

Influence of Temperature on the Performance of Gas Diffusion Electrodes in the CO2 Reduction Reaction

“…model" must be used, because film diffusion limitation of CO 2 is the maximum limitation possible. [72,73] All situations in between are described by the "thin film flooded agglomerate model". [74,75] Corresponding to the flooded agglomerate model it is assumed that CO 2 mass transport into flooded agglomerates of carbon nanoparticles takes place in order to reach the SnO x active sites supported on carbon (see the Supporting Information).…”

Heat and mass transfer analysis of bacon-type hydrogen-oxygen fuel cells: the volume average velocity

“…In developing the equations representing the heat transfer phenomena taking place in the porous electrodes and electrolyte, the temperature distribution in the y-direction is assumed to be uniform based on previous analysis [1]. The heat generated by the irreversibility of the reactions, under current drain, for Bacon-type microelectrodes is calculated by adopting the polarization of the electrodes represented in [5,11]. Previous analysis [1] has indicated that heats of solution/dilution are negligible for the range of electrolyte concentrations encountered in normal fuel cell operation.…”

A Method for Characterizing the Structure of Hydrophilic Porous Gas Diffusion Electrodes

“…[9] gives G = s/T [10] If s 9 9 = U, where U is the porosity, then substitution in Eq. If the resistivity factor R"/R' is called G, substituting in Eq.…”