A variable temperature study of the transport properties of aqueous solutions of VOSO4 and NH4VO3 in 2 M H2SO4

• Ion and proton transport processes mediated strongly by viscosity.
• Activation energies calculated from ionic conductivity and solution viscosity.
• Greater metal ion concentration ion association more prevalent for vanadyl ion.

Variable temperature ionic conductivity, viscosity and 1H NMR spin-lattice relaxation times, linewidths and chemical shifts measurements were determined for various concentrations of aqueous ammonium metavanadate (NH4VO3) and vanadyl sulfate (VOSO4) over the temperature range of 20–100 °C. Concentration ranges of 0.05–2 M and 0.05–0.2 M were investigated for VOSO4 and NH4VO3 respectively in 2 M H2SO4. Results show ion and proton transport processes that are mediated strongly by increasing solution viscosity, especially in the case of VOSO4. Activation energies calculated from ionic conductivity and solution viscosity show greater energy being needed for translational ion dynamics with increasing concentration for both solutions. Additionally, data suggest that with greater metal ion concentration ion association is more prevalent for the vanadyl ion. The differences between the transport capabilities of the two solution are discussed in terms of the 1H NMR, ionic conductivity and viscosity data.