Application of hydrogen—palladium and deuterium—palladium electrodes in the coulometric—potentiometric determination of bases in some dipolar aprotic solvents

The application of H2Pd and D2Pd electrodes as indicator, generator and reference electrodes in coulometric—potentiometric titrations of bases in acetonitrile, benzyl cyanide, nitromethane, ethylene carbonate and sulfolane, was investigated. Current—potential curves for hydrogen and deuterium dissolved in palladium, titrated bases, indicator and solvents show that hydrogen and deuterium are oxidized at potentials which are more negative than those of the titrated base and other components present in the solution. The generated H+ and D+ ions were used for the titration of organic bases (tributylamine, collidine, 2,2-bipyridine, cyclohexylamine, N,N-diphenyl guanidine, butylamine and quinoline) with visual and potentiometric titration end-point detection. The current efficiency was 100%. H2Pd and D2Pd electrodes were applied as indicator and reference electrodes.