Electrochemical and quantum chemical studies of peculiarities of 2,5-di-Me-pyrazine-di-N-oxide oxidation in the presence of methanol at single-walled and multi-walled carbon nanotube paper electrodes

Abstract

The use of methanol (MeOH) in direct methanol fuel cells has increased the interest in the search for new electrode materials and catalysts that allow the oxidation of MeOH to be carried out under conditions that satisfy their practical applications: low cost, stability, and high catalytic activity. In this work, electrochemical and quantum chemical methods were used to study peculiarities of the electrocatalytic system 2,5-di-Me-pyrazine-di-N-oxide–methanol at single-walled and multi-walled carbon nanotube (CNT) paper electrodes in comparison with a glassy carbon (GC) electrode in 0.1 M Bu₄NClO₄ solution in acetonitrile (MeCN). The adsorption energies of MeOH, CH₃COOH and H₂O on the CNT surface were determined by quantum chemical modeling; this opened the door for the explanation of effects found in the Pyr₁–MeOH catalytic system and for the ascertainment of factors affecting the catalytic efficiency of the process at CNT electrodes. We believe that this research will be helpful in using this process in electrocatalysis, sensors and direct methanol fuel cells, since the deactivation of aromatic di-N-oxides (as opposed to processes involving noble metals or noble metal oxides) is insignificant.