Reinert-Berg reaction

All the above methods, when hers are present, have one very serious drawback many hers give rise to a compact reaction layer, as described in Chap. 2. The above Reinert-Berg reaction does not, but the EC reaction,... 

In the Reinert-Berg system, the homogeneous chemical reaction involves a bulk species, and there is no reaction layer (Sect. 2.2.6). 

One of the simplest examples of a homogeneous chemical reaction (her) is the Reinert-Berg system [464], in which an electroactive species is generated, for example by means of a light flash, and then reduced as a Cottrell system, while the species decays chemically with a first-order reaction. The reactions are then... 

Here the value of the boundary concentration is specified. A familiar example in the present context is the outer boundary, beyond the diffusion space, where the concentration usually remains at the initial bulk value during the whole period over which the simulation is carried out. This also applies to the case of the Reinert-Berg mechanism (page 20), in which the bulk concentration itself changes with time, but we know the bulk value at any time, because chemical reaction kinetics, uncomplicated by transport effects, is well understood. In such cases, we can set a given bulk concentration, albeit time-varying. Another familiar example arises from the Cottrell experiment, in which the concentration at the electrode, Co, is set to zero. This is a particular case of that concentration being set to a definite value, not necessarily zero. 

As described in Chap. 5, for the simulation of a first order homogeneous chemical reaction her) coupled to diffusion such as the Reinert-Berg mechanism (5.11) we have the governing equation... 

Here, we simulate a system where a chemical reaction takes place in solution. An electroactive species is produced in solution, homogeneously distributed at bulk concentration Cj, by a radiation flash. The species decays with a first order chemical reaction. A potential is applied to the electrode such that the diffusion limited current is measured this corresponds to the Cottrell experiment on a decaying species. Reinert and Berg (1962) have solved this system analytically and found the ratio r of current at time t to the (diffusion) current i, in the absence of the chemical reaction ... 

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