Electrocatalytic Oxidation of Amines by Ni(1,4,8,11-tetraazacyclotetradecane)²⁺ Entrapped in Sol-Gel Electrodes

NiL²⁺ (L = 1,4,8,11-tetraazacyclotetradecane) was entrapped in sol-gel matrices in the presence of graphite. The matrices thus prepared serve as electrocatalysts for the oxidation of amines. The results point out that: (1) It is easy to prepare electrocatalytic electrodes by using this approach. (2) The properties of the electrodes thus prepared depend on the nature of the precursors used to prepare the matrices. (3) The mechanism of the electrocatalytic process differs from that observed in homogeneous solutions and depends on the nature of the electrode. (4) The matrix protects NiL²⁺ against the oxidation of the ligand.