Fenton test ferrous ions

The presence of phosphoric acid makes the chemistry in the Fenton test far more complex [69]. Firstly, the presence of phosphoric acid was shown to suppress the formation of radicals due to the lowered pH. Secondly, it was suggested that the presence of phosphoric acid further suppressed the degradation rate, possibly due to the formation of iron phosphates or by the ionization of the polymer. It was concluded that the presence of ferrous ion in the membrane-electrode interface had a negative impact on the fuel cell durability. However, this effect was mainly connected to the deterioration of the catalyst activity [69]. 

Table 1 provides information on commonly implemented accelerated tests. The OCV test, which was mentioned before, has an advantage in the fact that its experimental conditions are close to the operational conditions. However, the OCV test can be influenced by impurities in the electrode. In contrast, the Fenton reagent test is easy to implement. However, this test is far from the operational conditions, that is, the test is conducted in an aqueous solution, and contains a large number of ferrous ions. Therefore, a new accelerated degradation method was developed. 

NMR, mass spectroscopy, and various chromatographic techniques. Among the accelerated life tests used in fuel cell systems, Fenton s reagent, a combination of ferrous ions and aqueous hydrogen peroxide, is a well-known method for generating peroxide radicals at temperatures that mimic fuel cell operation (Fig. 2.30) [157],... 

---