Scholarlink

<p>Bipolar membranes operated under reverse-bias (r-BPM) provide the only potential route to use anodes free of platinum group metals in CO<sub>2</sub> electrolyzers when paired with the oxygen evolution reaction. Under 100% water dissociation efficiency (WDE) conditions, the OH<sup>−</sup> generated by a r-BPM fully replenishes the OH<sup>−</sup> consumed by the oxygen evolution reaction, maintaining an alkaline anolyte. However, unwanted co-ion crossover leads to &lt;100% WDEs, gradually causing anolyte acidification and nickel-based anodes to corrode over time. Here we experimentally measured the WDE of r-BPMs in a membrane–electrode assembly configuration as a function of the current density, anolyte concentration and cation identity, finding that the highest measured WDE of 98% is insufficient to maintain an alkaline environment over extended operation. We further highlight through modeling that WDEs &gt;99.8% are required to operate for &gt;10,000 h with reasonable anolyte volumes. Our results show that r-BPMs CO<sub>2</sub> electrolyzers require additional strategies, such as reverting to platinum group metal anodes or regenerating the anolyte, to operate stably at an industrial scale.</p><p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Water dissociation efficiencies control the viability of reverse-bias bipolar membranes for CO2 electrolysis

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年11月17日

查看全文
  • Gerard Prats Vergel,
  • Huan Mu,
  • Nikita Kolobov,
  • Jasper Biemolt,
  • David A. Vermaas,
  • Thomas Burdyny

摘要

Bipolar membranes operated under reverse-bias (r-BPM) provide the only potential route to use anodes free of platinum group metals in CO2 electrolyzers when paired with the oxygen evolution reaction. Under 100% water dissociation efficiency (WDE) conditions, the OH− generated by a r-BPM fully replenishes the OH− consumed by the oxygen evolution reaction, maintaining an alkaline anolyte. However, unwanted co-ion crossover leads to <100% WDEs, gradually causing anolyte acidification and nickel-based anodes to corrode over time. Here we experimentally measured the WDE of r-BPMs in a membrane–electrode assembly configuration as a function of the current density, anolyte concentration and cation identity, finding that the highest measured WDE of 98% is insufficient to maintain an alkaline environment over extended operation. We further highlight through modeling that WDEs >99.8% are required to operate for >10,000 h with reasonable anolyte volumes. Our results show that r-BPMs CO2 electrolyzers require additional strategies, such as reverting to platinum group metal anodes or regenerating the anolyte, to operate stably at an industrial scale.