Mechanism transition of mixed diffusion and charge transfer-controlled to diffusion-controlled oxygen reduction at Pt-dispersed carbon electrode by Pt loading, Nafion content and temperature

Theoretical and Experimental Approaches to Oxygen Reduction at Porous Composite Electrodes for Fuel Cells by Analyses of ac‐Impedance Spectra and Potentiostatic Current Transients

“…The theoretical treatment for the PCT by an analytical calculation allows us to extract quantitative estimates of kinetic parameters for the electrochemical reactions at porous electrodes. In addition, the analyses from the PCTs can substantiate the validity of the results of ac‐impedance spectra with respect to the oxygen reduction mechanism 17–22 .…”

“…The PCT technique has proven to be a reliable and powerful tool for the investigation of the reaction mechanism at porous cathodic electrodes in fuel cells 17–22 . One of the major advantages of the PCT technique is that the theoretical treatment involved is simpler and easier than that for the cathodic potentiodynamic polarisation method, since the current‐time relation in the PCT can be successfully obtained from the inverse Laplace transform of the electrode impedance or the analytical approach based upon the rate‐determining steps.…”

Cyclic voltammetry of electroactive and insulative compounds in solid state: A revisit of AgCl in aqueous solutions assisted by metallic cavity electrode and chemically modified electrode

“…(2) corresponds to charge transfer control and diffusion control, respectively, but those cases with 0.5 < n < 1.0 should be a result of both controlling factors being comparably and simultaneously influential, i.e. the reduction of AgCl is under the so called mixed control [38][39][40]. It should be pointed out that a similar form of Eq.…”

“…However, the 3PI penetration into the insulator is much slower, mainly because the mass diffusion through the reduction generated porous metal layer when it becomes sufficiently thick [29,41]. If the two processes occur simultaneously at different locations in the electrode, the overall current would be under the so called mixed control of charge transfer and mass diffusion [38][39][40]. Such a situation is highly likely present at some stages in the electro-reduction of AgCl as exemplified in Fig.…”

Durability of PEM fuel cell electrocatalysts prepared by microwave irradiation technique

“…1 illustrates the cyclic voltammograms of Pt/C (20%) ETEK catalyst having different C/N ratios in the catalyst ink taken at a scan rate of 50 mV/s for 50 cycles between 0 and 1.2 V potential ranges before and after Pt dissolution/agglomeration. In order to get a better network between the catalyst and the Nafion membrane, Nafion solution is added to the catalyst layer in PEM fuel cells and its role as a proton pathway is highly critical [31,32]. The ESAs obtained before and after degradation test for the inks having C/N ratios of 4, 8 and 12 were 18, 30 and 24 m 2 /g Pt and 10, 20 and 17 m 2 /g Pt, respectively.…”