Cyclic voltammetry was used to study properties of the [110] surface of a rutile (TiO2) monocrystal and its interaction with vanadium(V) species at conditions simulating typical preparation procedures for catalysts. It was found that vanadium enters the crystal lattice of rutile as a tetravalent ion and cannot be electrochemically oxidized to pentavalent but can easily be reduced to the trivalent oxidation state. A second vanadium species may also appear on the surface of rutile, which may be both reduced from +5 through +4 to +3 and oxidized from +3 through +4 to +5 oxidation state.