Efficient and facile electrochemical synthesis of sodium perborate using boron-doped diamond anode

Electrochemical oxidation offers a sustainable alternative to conventional oxidant production. Yet, the electrosynthesis of sodium perborate (SPB) has remained difficult due to its narrow stability window in aqueous solution and competition of oxygen evolution reaction under high potential. Although boron-doped diamond (BDD) electrodes are well known for enabling high-potential anodic reactions, their applicability to perborate synthesis has previously been questioned. Here, we demonstrate a robust, reproducible, and practical one-step electrochemical route to sodium perborate monohydrate (SPB-1) that directly yields a stable crystalline product using a BDD anode in concentrated carbonate/bicarbonate electrolytes. Systematic variation of operating parameters reveals that low temperature (3.5 °C), moderate-to-high current density (0.825–0.875 A cm⁻²), controlled amount of the applied charge (24–26 F), and sufficient post-electrolysis mixing (>20 min) are essential for efficient perborate formation. Under optimized conditions, the process achieves an isolated yield of 79 ± 3%, an active oxygen content of 14.0 ± 0.6%, and a current efficiency of 26 ± 1% across five independent runs, demonstrating excellent reproducibility and product quality comparable to commercial SPB-1. ... mehrCyclic voltammetry and galvanostatic anode potential measurements reveal that carbonate oxidation on BDD occurs at highly positive potentials overlapping with the oxygen evolution region, rationalizing the narrow optimal current density window and the superior performance of BDD relative to platinum anodes. FTIR analysis confirms the formation of SPB-1, with all characteristic vibrational features matching those of authentic material. Overall, this work establishes a reliable electrochemical strategy for SPB-1 synthesis, supported by mechanistic insight and quantitative benchmarking, and highlights the potential of BDD-based electrolysis for sustainable and scalable oxidant production.