Assessment of the electrochemical production of sodium perborate

Abstract

BACKGROUND

The convenient operating conditions for the electrochemical production of sodium perborate were first estimated by using a rotating ring-disc electrode. Based on these results two reactors – cylindrical batch and a recirculating parallel-plate arrangement coupled with a reservoir – were examined, employing as anolyte a solution of sodium carbonate, borax and sodium silicate as a stabilising agent. With the use of the recirculating system the behaviour of platinum and boron-doped diamond as anode materials was analysed, employing also different separators between the anodic and cathodic compartments.

RESULTS

The recirculating system with a platinum anode showed suitable performance at a current density of 100 mA cm⁻² and a temperature of 10 °C. Under these operating conditions, the sodium perborate concentration was 97.6 mmol L⁻¹ with a current efficiency of 21.4%. The specific energy consumption was 1.9 kW h mol⁻¹ and the space–time yield was 29.3 mol m⁻³ h⁻¹.

CONCLUSION

A powder of monohydrate sodium perborate was obtained with 20 g L⁻¹ NaOH as the initial catholyte concentration, alkalised the anolyte after electrolysis, settled at 10 °C, and after drying in a vacuum oven at 40 °C. The particles form oblong-shaped agglomerates of different sizes, of the order of 50 μm. Thus the electrosynthesis of this oxidising agent is appraised as an alternative procedure to the chemical method. © 2025 Society of Chemical Industry (SCI).