Vanadium Molecular Sieve, Vapo-5: Preparation and Electrochemical Characterization

The vanadium containing molecular sieve VAPO-5 was characterized by using cyclic voltammetry. The as-synthesized and calcined samples contain loosely bound VO2+ species that can be removed by immersion in the aqueous electrolyte solution. The steady-state cyclic voltammograms of VAPO-5 reveal two distinct reversible V(5+)/V(4+) processes centered at Eeq(I) = 0.11 V/SCE and Eeq(II) = −0.07 V/SCE. These processes have been proposed to arise from framework vanadium located at structurally distinct sites V-O-T (T = Al or P).