NaBH₄ is a promising hydrogen storage material, while faced with enormous difficulties for scale-up application due to regeneration issues. In this study, a highly efficient and economical strategy for the electrosynthesis of NaBH₄ from hydrolysis by-product NaB(OH)₄ has been proposed. By fabricating solid-phase electrodes with NaB(OH)₄ and electrocatalyst etc., the mass transfer process of B(OH)₄^- at the cathode surface was remarkably improved, thus reducing the resistance of the cathodic reaction. Meanwhile, XPS, FTIR, and CV analyses were combined to reveal the reaction path and control steps of B(OH)₄^- reduction to BH₄⁻ in the electrocatalytic system. The formation of NaBH₄ and intermediates (BH(OH)₃^-, BH₂(OH)₂^-, and BH₃(OH)^-) is the gradual replacement of (OH)^- in NaB(OH)₄ by H⁻. Furthermore, this study reveals that PbO has a suitable hydrogen evolution overpotential and excellent selective catalytic activity. The current efficiency for NaBH₄ synthesis via solid-phase electrolysis was up to 68.12 % by systematically regulating various factors.

NaBH ₄是一种很有前景的储氢材料，但由于再生问题，其规模化应用面临着巨大的困难。在本研究中，提出了一种从水解副产物NaB(OH) ₄电合成NaBH _{4的高效且经济的策略。通过NaB(OH) 4}和电催化剂等制作固相电极，显着改善了B(OH) ₄ ^-在阴极表面的传质过程，从而降低了阴极反应的阻力。同时，结合XPS、FTIR和CV分析揭示了电催化体系中B(OH) ₄ ^-还原为BH ₄ ^{-的反应路径和控制步骤。}_{NaBH 4}和中间体(BH(OH) ₃ ^-、BH ₂ (OH) ₂ ^-和BH ₃ (OH) ^- )的形成是NaB(OH) _4中的(OH) ^-逐渐被H ^-取代。此外，该研究表明PbO具有合适的析氢过电势和优异的选择性催化活性。_{通过系统调节各种因素，固相电解合成NaBH 4}的电流效率高达68.12%。