An Experimental Investigation of the Effect of Platinum on the Corrosion of Cathode Carbon Support in a PEMFC

Abstract

The possible role of platinum in the carbon corrosion at cell voltage higher than 1.0 V is controversial yet. To gain more insights into this issue, a square-wave potential cycles between 1.0 to 1.5 V was applied to fuel cells comprising cathodes with and without Pt. Using online non-dispersive infrared spectroscopy, we showed that Pt catalyzed the gasification of carbon in the early stage, while upon prolonged exposure to potential cycling (� 3 h), platinum started to hinder the CO 2 production. Based on cyclic voltammetry tests and Raman spectroscopy, the inhibiting effect of platinum on the corrosion was suggested to originate from modifications on carbon surface, where the formation of electroactive sites was limited. Electrode and nonelectrode ohmic resistances were distinguished further through electrochemical impedance spectroscopy measurement and the changes in electrode microstructure and surface composition were examined by scanning electron microscope image and energy dispersion X-Ray spectroscopy. The results indicated that Pt reduced the damage of electrode structures after potential cycles.That Pt catalyzed carbon corrosion below 1.0 V is always observed and widely accepted. [8,10,11] However, the catalytic role [a] F.

Atomically Dispersed Metal‐Based Catalysts for Zn–CO2Batteries

“…The main reason for this issue is that atomically dispersed metal sites are usually embedded in the carbon‐rich matrix, which may suffer from carbon corrosion at the high oxidative potential of OER. [ 110 ] Therefore, improving the graphitization degree of carbon matrix or developing non‐carbon substrate substitutes with high stability and high specific surface area are encouraged. In addition, increasing the OER activity of the cathode can not only reduce the charging voltage, thus slowing down the carbon corrosion and improving the stability of Zn–CO 2 batteries, but also enhance the energy efficiency of the battery.…”

Corrosion and Materials Degradation in Electrochemical Energy Storage and Conversion Devices

“…The primary degradation mechanisms of Pt/C are proposed to be Pt nanoparticle‘s aggregation and associated merger or detachment from the support and electrochemical Ostwald ripening, yielding Pt ions and their redeposition onto bigger particles [182–184] . On the other hand, the presence of Pt is suggested to cause a catalytic increase in C‐corrosion [120,185,186] . Continuous oxidation/reduction of the Pt will lead to the Pt ion‘s dissolution in the ionomer [127,187] .…”

“…Providing more details in this direction is out of the scope of this review. Clear fundamentals can be found elsewhere [112,122,131,149,182–188] …”

“…[182][183][184] On the other hand, the presence of Pt is suggested to cause a catalytic increase in C-corrosion. [120,185,186] Continuous oxidation/reduction of the Pt will lead to the Pt ion's dissolution in the ionomer. [127,187] PEM and ionomer degradations are other issues.…”

“…Clear fundamentals can be found elsewhere. [112,122,131,149,[182][183][184][185][186][187][188] A few recent works are available on galvanic corrosion, [189] and corrosion issues specific to other fuel cell types, including solid oxide, [190][191][192][193] microbial [194] and direct carbon [195] fuel cells.…”