Role of non-covalent interactions in 2,5-di-Me-pyrazine-di-N-oxide - tertiary butyl alcohol - single-walled and multi-walled carbon nanotubes electrocatalytic systems

Abstract

Oxidation of tert-butyl alcohol (tert-BuOH, Me₃COH), a compound with a high C-H bond breaking energy in the absence of precious metals or their oxides as catalysts and using metal-free electrodes, is an inexpensive process and is of interest for practical applications in electrocatalysis and sensors.

In this work, electrocatalytic systems 2,5-di-Me-pyrazine-di-N-oxide (Pyr₁) - tert-BuOH – single - walled (SWCNT) and multi-walled (MWCNT) carbon nanotube paper electrodes in 0.1 M Bu₄NClO₄ solution in acetonitrile (MeCN) were studied by the methods of cyclic voltammetry, quantum chemical modeling and electron paramagnetic resonance (EPR) electrolysis. Calculaition of energies of non-covalent interactions between the components of the electrocatalytic system in complexes Me₃COH^*Me₃COH, Me₃COH^*MeCN, Pyr₁^*Me₃COH and the adsorption energy of Me₃COH and complexes of Pyr₁^*Bu₄NClO₄, Pyr₁^*Me₃COH, Pyr₁^*MeCN and Me₃COH ^*Bu₄NClO₄ on CNTs surface using a cluster model describing the surface of conducting carbon nanotubes (10, 10) was performed. The study made it possible to reveal the regularities characteristic of aromatic-di-N-oxide – CNT electrocatalytic systems and to propose a mechanism of tert-BuOH oxidation in the presence of electrochemically generated radical cation Pyr₁. The data will be useful at using CNT electrodes in electrocatalytic processes, as well as aromatic di-N-oxide-CNT catalytic systems in electrocatalysis and sensors.