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Ni(II)cyclam Catalyzed Reduction of CO 2 – Towards a Voltammetric Sensor for the Gas Phase
Author(s) -
Jacquinot P.,
Hauser P. C.
Publication year - 2003
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200302743
Subject(s) - electrode , cyclam , electrochemistry , catalysis , detection limit , potentiometric titration , selectivity , analytical chemistry (journal) , diffusion , supporting electrolyte , electrolyte , phase (matter) , chemistry , inorganic chemistry , materials science , chromatography , organic chemistry , metal , physics , thermodynamics
The detection of CO 2 in the gas phase is possible in presence of oxygen with an amalgamated Au‐poly(tetrafluoroethylene) gas diffusion electrode and an internal electrolyte solution containing Ni(II)cyclam. For concentrations between 0.1 to 1% the electrochemical cell has a sensitivity of 3.58 mA % −1 and the detection limit is 500 ppm. In preliminary experiments at rotating disk electrodes the optimum pH‐range was found to be between 3.5 to 6 and a selectivity ratio of the catalyst for CO 2 /H + of 5 : 1 could be determined. The relationship between reduction current and the square root of the angular speed is linear, indicating that the electrochemical process is limited by diffusion of CO 2 . Tl and Pb are presented as alternative electrode materials at which the Ni(II)cyclam catalyzed reduction of CO 2 can be observed. Problems arise from fouling effects at the sensing electrode and a non‐linearity of the calibration plot at higher concentrations.