Electrochemical activity of Ni-montmorillonite/Vulcan XC-72R carbon black nano-catalyst for the oxidation of methanol in acidic medium

摘要

Direct methanol fuel cell is claiming to be the most main power source in future as a clean energy source, for which methanol is used as fuel. In the present study, nickel nanoparticles were synthesized by green route in the presence of montmorillonite (Ni-MMT). Then the electrochemical activity of prepared nanocomposite was investigated in methanol oxidation reaction in acidic medium. In the process of nickel nanoparticle synthesis, the natural substrate montmorillonite was used as capping agent and Allium jesdianum water extract was used as the source of reducing agent for the first time. The Ni-MMT sample was characterized by UV–Vis, XRD, SEM and EDX techniques. Production of nickel nanoparticles in the proposed green method is confirmed by absorption peak of 405?nm in UV–Vis spectrum. The average particle size of Ni-MMT was determined as 20.80?nm. The oxidation of methanol in acidic medium was studied by cyclic voltammetry using Ni-MMT-modified carbon paste electrode (Ni-MMT/CPE). Methanol was oxidized on the modified electrode surface at 0.3?V. Also, the catalytic current of methanol oxidation was 3?mA in H~(2)SO~(4)electrolyte which is significantly more than unmodified CPE. The concentration of 0.5?M for H~(2)SO~(4)was obtained as the optimum electrolyte for the oxidation of methanol. Methanol can be catalyzed in the concentration range of 0.1–0.5?M by the prepared nanostructured catalyst. Graphic abstract Ni nanoparticles in montmorillonite (Ni-MMT) which was prepared by Allium jesdianum extract have a good electrocatalytic effect on methanol oxidation.