Carbon Atoms In The Line For The Electrochemical Oxidation Of Methanol

Carbon atom wires (CAWs), a new novel carbonaceous material synthesized in our lab, act as both of a catalyst carrier and a catalyst promoter in electrochemical oxidation of methanol.The morphology and structure of the pyrolytic product of CAWs were characterized by transmission electron microscope (TEM) and X-ray diffraction (XRD). The catalysis of the Pt/CAWs/G electrode on electrochemical oxidation of methanol was demonstrated by cyclic voltammetry. Experimental results showed that, the Pt surface area increased by 1 time and anodic peak current of cyclic votammograms (CVs) increased by 1.4 times on the Pt/CAWs/G electrode, compared to the Pt/XC/G electrode, at which Pt was carried on active carbon VulcanXC-72, when the same charge quantity was consumed to deposit Pt on these electrodes.The structure and morphology of CAWs depend on their synthetic conditions, such as catalyst quantity added and pyrolytic temperature applied in synthesis, which were investigated for the effects of Pt/CAWs/G electrode on electrocatalytic oxidation of methanol. The experimental results gave the optimal pyrolytic temperature of 750°C and the optimal mass ratio of 8‰, of the catalyst to pyrolytic precursor.Considering the similar chemical properties among Fe, Co and Ni, we tried to use Co or Ni, instead of Fe, as the catalyst in CAW preparation. Experimental results indicated that, with the same charge quantity for Pt deposition, the surface area of Pt on the Pt/CAWs_(Ni)/G electrode increase by 50% in comparison with the Pt/CAWs_(Fe)/G, or Pt/CAWs_(Co)/G electrode; the three electrodes almost have the same anodic peak current density of methanol oxidation on their CVs; the electrodes of Pt/CAWs_(Ni)/G and Pt/CAWs_(Co)/G showed little better stability compared to Pt/CAWs_(Fe)/G electrode.Nitric acid treatment on CAWs can improve their purity and increase functional groups such as hydroxyl and carboxylic acid groups attached on them, confirmed by the infrared spectra measured before and after the treatment respectively. With the same charge quantity consumed for Pt deposition, the anodic peak current density of methanol oxidation at CVs on the Pt/CAWs_(Nitric)/G electrode with nitric acid treatment, increased by 100% compared to the Pt/CAWs/G electrode without nitric acid treatment, although they have the same value of the surface area of Pt. The former electrode has much superiority over the latter on steadiness.