Electrical and electrochemical processes in solid tetrabutylammonium hydroxide hydrate

The electrical and electrochemical processes in solid tetrabutylammonium hy droxide hydrate (C4H9)(4)NOH . 30H(2)O (TBAOH30) have been studied in the t emperature range 80-305 K by impedance spectroscopy and linear sweep voltam metry. The shape of impedance spectra of an Au \ TBAOH30 \ Au cell depends on temperature. Except at the lowest temperatures, it exhibits at least two time constants. The electrical conductivity is similar to that of previous ly studied tetramethylammonium hydroxide hydrates. Approximately, linear Ar rhenius-type conductivity dependence is observed for higher and lower tempe ratures. The activation energies are equal to 0.31 and 0.18 eV, respectivel y. The electrochemical reaction: hydrogen evolution was studied in an Au \ (C4H9)(4)NOH . 30H(2)O \H-2(Pd) cell. Lowering of temperature cause a decre ase of cathodic current. At high overpotentials, an approximately linear se milogarithmic dependence of current density on overpotential is observed. T he activation energy of the electrochemical reaction is equal to 0.44-0.47 eV and larger than that of conductivity. The reasons for this difference ar e discussed. (C) 2001 Elsevier Science B.V. All rights reserved.