In this present study, a novel material made up of p-benzoquinone (BQ) immobilized on a new composite of cellulose acetate and mixed metal oxides (CA/TiO2/Sb2O5) was applied to the electrocatalytic oxidation of ascorbic acid (H2AA). The material was prepared by a phase inversion process and characterized by several techniques including scanning electronic microscopy coupled with energy dispersive spectroscopy (SEM–EDS), X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence. Ti and Sb mapping profiles on the surface showed a homogeneous distribution of the matrices. Ti2p and Sb3d doublet indicate that the formation of TiO2 and Sb2O5 is the presumed responsible for the good rigidity of the polymeric matrix. A carbon paste electrode of this material was used to study the electrocatalytic oxidation of ascorbic acid by cyclic voltammetric, chronoamperometric and differential pulse techniques. The electrode had a quick response time, showing great potential to be utilized as an electrochemical sensor for the determination of ascorbic acid in commercial samples.