Carbon-Based Cerium(III)-Doped Lead Dioxide Anode

Electro-catalytic activity of carbon based cerium doped lead dioxide anodes was investigated. Electrodes were prepared by electrodepositing lead dioxide on carbon based substrates from a bath comprising 1.0 M lead(II) nitrate and 0.1 M and cerium(III) nitrate. Polarization studies of cerium doped lead dioxide electrodes were carried out using 1.0 mM iso-propanol at scan rate 100 mV/min in a three electrode system as shown in Figure 1.

Electro-oxidation of chromium(III) to chromium(VI) was also carried out at the cerium doped lead dioxide electrode (area 30cm²) in a divided cell using 0.3 mM chromium(III) solution. Electrolysis was run for 20 hours and the electrolyte upon analysis by visible spectrophotometry yielded 77.4% conversion of chromium(III) to chromium(VI).

Figure 1: Anodic polarization curves: (a) bare carbon, (b) cerium(III)-doped lead dioxide and (c) cerium(III)-doped lead dioxide in 1.0 mM iso-propanol. Background electrolyte: 1.0 M sulphuric acid and E in volts vs. Ag/AgCl,Cl^-

Reference:

J. Kong, S. Shi, L. Kong, X. Zhua and J. Ni, Preparation and characterization of lead dioxide electrodes doped with different rare earth oxides, Electrochim. Acta, 53, 2048 (2007)

*Presently at School of Chemistry Monash University Clayton Victoria 3800 Australia