Influence of anode material on electrochemical decomposition of urea

摘要

Voltammetric investigations into the process of anodic decomposition of urea using Ti/Pt, Ti/(Pt-Ir){sub}(70:30), Ti/RuO{sub}2, Ti/(RuO{sub}2-TiO{sub}2){sub}(40:60), Ti/(RuO{sub}2-TiO{sub}2-IrO{sub}2){sub}(20:60:20), Ti/(Ta{sub}2O{sub}5-IrO{sub}2){sub}(70:30) electrodes have been carried out. Two anodes namely (Ti/(Pt-Ir){sub}(70:30) and Ti/(Ta{sub}2O{sub}5-IrO{sub}2){sub}(70:30)) were found to be stable enough and indicated the required activity to produce non-toxic N{sub}2 and CO{sub}2 in place of nitrites and nitrates, the commonly reported electrochemical urea oxidation products. The kinetics of the process in question using the above two electrodes was further examined in a periodic electrolyzer. The effect of the anodic current density (j = 2-10 A/dm{sup}2), initial urea concentration (C{sub}(0M) = 1-10 g/dm{sup}3) and the concentration of sodium chloride (c{sub}(NaCl) = 1-10 g/dm{sup}3) on basic process indices (average rate of urea decomposition, a; current efficiency, W{sub}p, and unit DC power consumption, Z{sub}j) was discussed.