Mavrikis Sotirios, Göltz Maximilian, Rosiwal Stefan, Wang Ling, Ponce de León Carlos
Electrochemical Engineering Laboratory, Energy Technology Research Group Faculty of Engineering and Physical Sciences, University of Southampton Highfield Campus, University Road, Southampton, SO17 1BJ, United Kingdom.
National Centre for Advanced Tribology at Southampton (nCATS) Faculty of Engineering and Physical Sciences, University of Southampton Highfield Campus, University Road, Southampton, SO17 1BJ, United Kingdom.
ChemSusChem. 2022 Feb 18;15(4):e202102137. doi: 10.1002/cssc.202102137. Epub 2022 Feb 2.
Electrochemical synthesis of hydrogen peroxide (H O ), via the two-electron water oxidation reaction (2e WOR), is an attractive method for the sustainable production of valuable chemicals in place of oxygen during water electrolysis. While the majority of 2e WOR studies have focussed on electrocatalyst design, little research has been carried out on the selection of the supporting electrolyte. In this work, we investigate the impact of potassium carbonate (K CO ) electrolytes, and their key properties, on H O production. We found that at electrolyte pH values (>9.5) where the carbonate anion (CO ) was prevalent in the mixture, a 26.5 % increase in the Faraday efficiency (%FE) for H O production was achieved, compared to bicarbonate (HCO ) dominant solutions. Utilising boron-doped diamond (BDD) in highly concentrated K CO solutions, current densities of up to 511 mA cm (in 4 m) and %FEs of 91.5 % (in 5 m) could be attained. The results presented in this work highlight the influence of CO on electrochemical H O generation via the 2e WOR and provide novel pathways to produce desirable commodities at the anode during electrochemical water splitting.
通过两电子水氧化反应（2e WOR）电化学合成过氧化氢（H₂O₂），是一种在水电解过程中替代氧气可持续生产有价值化学品的有吸引力的方法。虽然大多数2e WOR研究都集中在电催化剂设计上，但在支持电解质的选择方面开展的研究很少。在这项工作中，我们研究了碳酸钾（K₂CO₃）电解质及其关键性质对H₂O₂生成的影响。我们发现，在电解质pH值（>9.5）时，混合物中碳酸根阴离子（CO₃²⁻）占主导，与以碳酸氢根（HCO₃⁻）为主的溶液相比，H₂O₂生成的法拉第效率（%FE）提高了26.5%。在高浓度K₂CO₃溶液中使用硼掺杂金刚石（BDD），可实现高达511 mA cm⁻²（在4 m时）的电流密度和91.5%（在5 m时）的%FE。这项工作中呈现的结果突出了CO₃²⁻对通过2e WOR进行电化学H₂O₂生成的影响，并为在电化学水分解过程中在阳极生产所需产物提供了新途径。
