Electrochemical reduction of NOx - DTU Orbit

3.1.3 3-electrode pellet set-up
3 Experimental
In Figure 3 a principle sketch of the 3 electrode pellet (3EP) set-up is shown. The geometric design
of the 3EP was determined in the work by Winkler et al. 104 as a very well suited design for
characterisation of solid oxide electrodes due to the assurance of a uniform current distribution at
the working electrode. The 3EP set-up makes it possible to perform electrochemical
characterisation by use of reference electrode with a well-defined potential, which means the
exact potential of the working electrode during the measurements may be determined.
Furthermore the outlet gas from the working electrode in this set-up can be analysed to detect
NOx-conversion. During this project the outlet gas was analysed by chemiluminiscence detector,
which will be described further in section 3.5. The advantage of the 3EP set-up is it allows for a
detailed electrochemical characterisation of the solid oxide electrode in combination with gas
conversion measurements. The disadvantage is the 3EPs are fairly time-consuming to produce and
only one 3EP can be tested at a time.
Figure 3. Set-up of 3-electrode pellet, note in this work CGO electrolyte was used instead of YSZ
electrolyte as stated in the image.
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