Construction of a Microchannel Aeration Cathode for Producing H2O2 via Oxygen Reduction Reaction
Construction of a Microchannel Aeration Cathode for Producing H2O2 via Oxygen Reduction Reaction
复制标题
氧还原反应生产H2O2的微通道曝气阴极的构建
DOI：
10.1021/acsami.1c14969
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发表时间：
2021
影响因子：
9.5
通讯作者：
Yu Hongtao
中科院分区：
文献类型：
--
作者：
Gu Yuwei;Wu Shuai;Cao Yujia;Liu Meng;Chen Shuo;Quan Xie;Yu Hongtao
电化学氧还原是一种很有前途的原位生成h2o2的方法。它的重要前提是溶解氧分子必须扩散到并到达阴极表面与电子反应。显然，缩短扩散距离有利于提高反应效率。在本研究中，提出了一种新的微通道曝气模式，将o2的扩散距离限制在微米级。在这种模式下，用碳块和微通道阵列制作了一个曝气阴极。每个通道的直径仅为10 ~ 40 μm。氧气将从顶部入口泵入每个微通道，而水溶液将通过底部入口和通道壁上的孔隙渗透到微通道中。该微通道曝气阴极的h2o2产率高达4.34 mg h-1cm-2，是普通鼓泡曝气方式的8倍左右。相应的能耗仅为7.35 kWh kg-1，优于大多数报道的结果。除了H2O2，曝气阴极还可以通过H2O2的单电子还原产生•OH。与h2o2和•OH结合，苯酚、磺胺甲恶唑和阿特拉津均能有效降解。我们期望这种微通道曝气阴极可以激发人们对h2o2生成、水污染物控制和其他多相界面反应的研究。
Electrochemical oxygen reduction is a promising method for in situ H2O2production. Its important precondition is that dissolved oxygen molecules have to diffuse to and arrive at the cathode surface for reacting with electrons. Obviously, shortening the diffusion distance is beneficial to improve the reaction efficiency. In this study, a novel microchannel aeration mode was proposed to confine the diffusion distance of O2to the micrometer level. For this mode, an aeration cathode was fabricated from a carbon block with microchannel arrays. The diameter of each channel was only 10–40 μm. Oxygen will be pumped into every microchannel from the top entry, while an aqueous solution will permeate into microchannels through the bottom entry and pores in the channel wall. This microchannel aeration cathode exhibited a H2O2yield of up to 4.34 mg h–1cm–2, about eight times higher than that of the common bubbling aeration mode. The corresponding energy consumption was only 7.35 kWh kg–1, which was superior to most reported results. In addition to H2O2, this aeration cathode may also produce•OH via a one-electron reduction of H2O2. In combination with H2O2and•OH, phenol, sulfamethoxazole, and atrazine were degraded effectively. We expect that this microchannel aeration cathode may inspire researchers focused on H2O2production, water pollutant control, and other multiphase interfacial reactions.