TY - JOUR
T1 - How changes in interfacial pH lead to new voltammetric features
T2 - The case of the electrochemical oxidation of hydrazine
AU - Arulrajan, Antony Cyril
AU - Renault, Christophe
AU - Lai, Stanley C.S.
PY - 2018/5/7
Y1 - 2018/5/7
N2 - The electrochemical oxidation of hydrazine was investigated in strongly and weakly pH buffered solutions to reveal the role of buffer capacity in proton-electron transfer redox reactions. In sufficiently buffered solutions, a single voltammetric feature was observed. However, increasing the hydrazine concentration (or, equivalently, moving to an insufficiently buffered solution) gave rise to a second voltammetric feature. These results are rationalised with a conceptually simple model and finite element simulations. We demonstrate that the new voltammetric feature is caused by a large change in the pH at the electrode surface as the reaction proceeds. Importantly, we show that the occurrence of additional voltammetric features are general for proton-electron transfer reactions in insufficiently buffered solutions, and should not be confused with changes in the reaction mechanism.
AB - The electrochemical oxidation of hydrazine was investigated in strongly and weakly pH buffered solutions to reveal the role of buffer capacity in proton-electron transfer redox reactions. In sufficiently buffered solutions, a single voltammetric feature was observed. However, increasing the hydrazine concentration (or, equivalently, moving to an insufficiently buffered solution) gave rise to a second voltammetric feature. These results are rationalised with a conceptually simple model and finite element simulations. We demonstrate that the new voltammetric feature is caused by a large change in the pH at the electrode surface as the reaction proceeds. Importantly, we show that the occurrence of additional voltammetric features are general for proton-electron transfer reactions in insufficiently buffered solutions, and should not be confused with changes in the reaction mechanism.
UR - http://www.scopus.com/inward/record.url?scp=85046672874&partnerID=8YFLogxK
U2 - 10.1039/c8cp01835a
DO - 10.1039/c8cp01835a
M3 - Article
AN - SCOPUS:85046672874
VL - 20
SP - 11787
EP - 11793
JO - Physical chemistry chemical physics
JF - Physical chemistry chemical physics
SN - 1463-9076
IS - 17
ER -