Electrochemical reduction of NOx - DTU Orbit

3.3 Impregnation
3 Experimental
The impregnation procedures used for impregnation of the screen-printed electrodes and the
tape-casted electrodes tested in this work are stated in the following two subsections. The two
different impregnation procedures are based on in-house procedures in the department and were
chosen, as they turned out to give functional results. The first method used for the screen printed
electrodes was a method developed in-house based on the method described by Sholklapper et
al. 105 but without using a gel-step. The second method used for tape casted electrodes was based
on the method described by Lundberg et al. for synthesis of high-surface-area CeO2 106 . It should be
emphasized that the procedures have not been carefully optimized, and some of the steps in the
procedures, like the use of a surfactant and vacuum during the impregnation, may turn out to be
unnecessary, if the impregnation methods are optimized.
3.3.1 Screen-printed electrodes
Impregnation of screen-printed electrodes involved the following steps:
1) Preparation of an aqueous precursor solution of the metal-nitrate
2) For the MnOx and the BaO impregnations purely aqueous nitrate solutions were used,
while for the KNO3 impregnation ≈1wt% Triton-X45 surfactant (Fluka) was added to the
impregnation solution, this addition of Triton-X45 may however have been unnecessary.
3) Immersion of the cells into precursor solution
4) Vacuum treatment of the cells immersed in the precursor solution for ≈10 s at pressure