Electrocatalytic oxidation of methanol by nickel stearate L-B film

The electrocatalytic oxidation of small organic molecules such as methanol has been extensively studied. In alkaline solution, nickel and its alloys are important catalysts for the oxidation of small organic molecules. Conductive polymer membrane electrodes embedded with nickel ions also have high electrocatalytic activity for small organic alcohols. The reaction does not produce intermediate of toxic catalysts. The electrocatalytic active center is nickel peroxide NiO (OH).

In this paper, nickel ions were immobilized on platinum substrates by L-B film for the first time. The electrocatalytic oxidation of small alcohols by L-B film in alkaline solution was studied. 1 The electrode of nickel stearate L-B film was used to prepare L-B film for JD-200 Film-drawing machine developed by Jilin University. The subphase was nickel nitrate secondary aqueous solution of 5.0 *10-4 Mo l/L, and the spreading solution was 1.0 *10-3 Mo l/L stearin. In acid chloroform solution, Pt sheet is used as the base, and the film is hanging vertically. The film pressure is controlled at (25-30)*10-3 N/m, the film hanging speed is 0.2-1.0 m m/min, and the temperature is about 23 centigrade.

RESULTS AND DISCUSSION 2.1 Voltammetric characteristics of nickel stearate L-B film electrode Fig. 1 shows the cyclic voltammetric curves of four layers of nickel stearate L-B film electrode in alkaline solution. The redox potential of nickel ion appears at 0.43 V and 0.33 V at the first potential scan (Fig. 1a); and the redox potential shifts negatively (0.38 V and 0.32 V) at the second scan, respectively. The peak deformation of E P is about 60 mV. With the increase of current, the electrochemical reaction showed good reversibility (Fig. 1b); after 60 minutes of potential scanning, the oxidation potential shifted to about 10 mV, while a small oxidation peak appeared at about 0.45 V (Fig. 1c), and the reduction potential remained basically unchanged; after 60 minutes of scanning, the oxidation potential shifted to 10 mV, and the small peak at 0.45 V remained unchanged (Fig. 1d). The concentration of KO H increased, and the oxidation potential remained unchanged (Fig. 1d). The reduction potential shifts negatively, the Ep decreases, and the peak deformation is sharp (Table 1). In order to maintain the electrical neutrality in the film, the reaction is also related to the mass transfer process of OH.

Electrocatalytic oxidation of methanol by nickel stearate L-B film