Li Zonglin, Feng Zhiyuan, Chen Min, Song Yankai, Dai Yicen, Mao Shun, Zhao Hongying
Shanghai Key Lab of Chemical Assessment and Sustainability, Key Laboratory of Yangtze River Water Environment, School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Water Res. 2025 Apr 1;273:122967. doi: 10.1016/j.watres.2024.122967. Epub 2024 Dec 12.
Selective conversion of organic pollutants in wastewater into value-added chemicals is a promising strategy for sustainable water management. Electrochemical processes offer attractive features of precise control over reaction pathway to achieve desired products, however, the traditional anode-mediated processes still face challenges of over-oxidation by the inevitably formed of hydroxyl radical (HO). Herein, we proposed a new cathode-mediated approach for selective conversion of phenol to p-benzoquinone (p-BQ) through peroxymonosulfate (PMS) activation. A core-shell layered mesoporous spherical iron-based carbon catalyst (denoted Fe/C-MS) was rationally designed to initiate the reactions, where the first shell layer composed of mesoporous carbon provided a confined environment to enrich PMS and phenols, and the electronic configuration of encapsulated Fe species favored the formation of high-valent ion-oxo species (Fe=O) during PMS activation. Notably, the electrochemical process with Fe/C-MS and PMS (denoted Fe/C-MS-E/PMS) achieved a high yield of p-BQ at 80.2 % and a selectivity of 93.7 % within 5 min, resulting in an ultra-low energy consumption (0.07 KWh/mol phenol). The p-BQ production rate reached an impressive value of 1002.5 %/h, 30-500 times higher than the traditional chemical and anodic oxidation methods. The applicability of this cathode-mediated process was further validated by its successful treatment of real coking wastewater, underscoring the potential as a sustainable strategy for selective conversion of phenol to desired products with high yield and low energy consumption. All the findings available in this study drive us to image that the long-neglected cathode-mediated process, if rationally designed, may serve as an attractive strategy for more sustainable resource recovery during wastewater treatment.
将废水中的有机污染物选择性转化为高附加值化学品是可持续水管理的一个有前景的策略。电化学过程具有精确控制反应路径以获得所需产物的吸引人的特性，然而，传统的阳极介导过程仍然面临着不可避免形成的羟基自由基（·OH）过度氧化的挑战。在此，我们提出了一种通过过一硫酸盐（PMS）活化将苯酚选择性转化为对苯醌（p-BQ）的新型阴极介导方法。合理设计了一种核壳层状介孔球形铁基碳催化剂（表示为Fe/C-MS）来引发反应，其中由介孔碳组成的第一壳层提供了一个受限环境以富集PMS和苯酚，并且封装的铁物种的电子构型有利于在PMS活化过程中形成高价离子氧物种（Fe=O）。值得注意的是，使用Fe/C-MS和PMS的电化学过程（表示为Fe/C-MS-E/PMS）在5分钟内实现了80.2%的高p-BQ产率和93.7%的选择性，导致超低能耗（0.07千瓦时/摩尔苯酚）。p-BQ的生产率达到了令人印象深刻的1002.5%/小时，比传统化学和阳极氧化方法高30 - 500倍。该阴极介导过程的适用性通过其成功处理实际焦化废水得到进一步验证，突显了其作为一种可持续策略以高收率和低能耗将苯酚选择性转化为所需产物的潜力。本研究中的所有发现促使我们设想，长期被忽视的阴极介导过程，如果合理设计，可能成为废水处理过程中更可持续资源回收的一种有吸引力的策略。
