Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene
Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene
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DOI：
10.1038/s41565-022-01277-z
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发表时间：
2022-12-19
影响因子：
38.3
通讯作者：
Wang, Hailiang
中科院分区：
文献类型：
--
作者：
Choi, Chungseok;Wang, Xiaoxiong;Wang, Hailiang
电化学为氯代有机物污染的环境水体提供了一种高效、可持续的处理方法。然而，目前1，2-二氯乙烷(DCA)的电化学价化面临着缺乏选择性地将水溶液中的DCA转化为乙烯的催化剂的挑战。在这里，我们报道了一种由组装在多壁碳纳米管上的酞菁钴分子组成的催化剂，它可以高电流和高能量效率地电化学分解水中的DCA。在宽的电极电位和反应物浓度范围内，乙烯以前所未有的类似于100%法拉第效率的高速率产生。动力学研究和密度泛函理论计算表明，速率控制步骤是第一个C-Cl键断裂，不涉及质子，这是一个关键的机理特征，使钴酞菁/碳纳米管能够有效地催化DCA脱氯和抑制析氢反应。催化剂的纳米管结构使我们能够将其塑造成流动带电的膜，我们已经使用它来演示在环境相关的DCA和电解质浓度下从模拟水样中>；95%的DCA去除。
Electrochemistry can provide an efficient and sustainable way to treat environmental waters polluted by chlorinated organic compounds. However, the electrochemical valorization of 1,2-dichloroethane (DCA) is currently challenged by the lack of a catalyst that can selectively convert DCA in aqueous solutions into ethylene. Here we report a catalyst comprising cobalt phthalocyanine molecules assembled on multiwalled carbon nanotubes that can electrochemically decompose aqueous DCA with high current and energy efficiencies. Ethylene is produced at high rates with unprecedented similar to 100% Faradaic efficiency across wide electrode potential and reactant concentration ranges. Kinetic studies and density functional theory calculations reveal that the rate-determining step is the first C-Cl bond breaking, which does not involve protons-a key mechanistic feature that enables cobalt phthalocyanine/carbon nanotube to efficiently catalyse DCA dechlorination and suppress the hydrogen evolution reaction. The nanotubular structure of the catalyst enables us to shape it into a flow-through electrified membrane, which we have used to demonstrate >95% DCA removal from simulated water samples with environmentally relevant DCA and electrolyte concentrations.