What is the onset potential of an oxygen reduction reaction?
The onset potential is estimated as 0.841 V, 0.877 V, 0.895 V, and 0.877 V, and the diffusion-limited current density is approximately 3.27 mA cm−2, 4.26 mA cm−2, 3.99 mA cm−2, and 3.43 mA cm−2 for Ru100/CNs, Pd33Ru67/CNs, Pd67Ru33/CNs, and Pd100/CNs at +0.3 V vs. RHE, respectively.
How do you find the onset potential?
The most appropriate way of determining onset potential is to draw tangents in non-faradaic zone (conventionally horizontal line) and faradaic zone in LSV curve. Abscissa of point where these two tangents intersect, gives the onset value.
What is onset potential in ORR?
The high ORR activity is also evident from its onset potential (~0.93 V) and half-wave potential (~0.79 V) in the RDE polarization curve (Figure 3b).
What is used for oxygen reduction as catalyst?
Platinum (Pt)-based catalysts have been unanimously considered the most efficient catalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs).
What is the onset potential?
The onset potential is the highest (for cathodic reactions) or lowest (for anodic reactions such as the OER) potential values at which a reaction product is produced at a given electrode and defined conditions.
Can oxygen be reduced or oxidized?
Oxidation and reduction in terms of oxygen transfer The terms oxidation and reduction can be defined in terms of the adding or removing oxygen to a compound. Oxidation is the gain of oxygen. Reduction is the loss of oxygen.
What is an onset potential?
What is open circuit potential?
Open circuit potential (OCP) is defined as the potential that exists in an open circuit. That is, it is the voltage present when the terminal ends of a circuit are detached, and there is no external load. Figure 1. When an electrode is immersed in an electrolyte, it will adopt an open circuit potential.
What is half wave potential?
Half-wave potential (E1/2) is a potential at which polarographic wave current is equal to one half of diffusion current (id). Observation of a current peak at a specific half-wave potential therefore identifies the chemical species producing the current.
Is oxygen a reduction reaction?
In chemistry, the oxygen reduction reaction refers to the reduction half reaction whereby O2 is reduced to water or hydrogen peroxide. In fuel cells, the reduction to water is preferred because the current is higher.
How does oxygen reduction work?
Oxygen reduction systems lower oxygen levels within the protected area by feeding in nitrogen generated on site.
What is an example of reduction reaction?
Reduction can be considered as the removal of oxygen, the addition of hydrogen, or the gain of electrons. Removal of oxygen: Metal ores which are oxides are reduced to the metal – this is how iron is made from iron ore. Copper oxide can be reduced to copper by heating it while passing hydrogen gas over it.
What is the onset potential of a catalyst?
The onset potential is one of the main parameters used to characterize and compare the performance of electrocatalysts. It helps to assess the efficiency of a material to catalyze specific reactions, as for instance, an oxygen reduction reaction (ORR) [1].
What is ORP (oxidation reduction potential)?
Oxidation-reduction potential (ORP) measures the ability of a lake or river to cleanse itself or break down waste products, such as contaminants and dead plants and animals. When the ORP value is high, there is lots of oxygen present in the water. This means that bacteria that decompose dead tissue and contaminants can work more efficiently.
What is oxygen reduction reaction (ORR)?
As the primary cathode reaction of the hydrogen-oxygen fuel cell technology, oxygen reduction reaction (ORR) is one of the most extensively studied reactions in electrochemistry [ [1], [2], [3], [4] ]. Surprisingly though, the high-cost platinum remains the catalyst of choice since the birth of the first fuel cell around 1840 [ 5 ].
What is the onset potential and why is it important?
It helps to assess the efficiency of a material to catalyze specific reactions, as for instance, an oxygen reduction reaction (ORR). Formally, the onset potential is defined as the potential where an electrochemical process starts.