Charging into epoxides Ethylene oxide is a strained, reactive molecule produced on a vast scale as a plastics precursor. The current method of synthesis involves the direct reaction of ethylene and oxygen at high temperature, but the original protocol relied on the reduction of chlorine to produce a chlorohydrin intermediate. Leow et al. report a room temperature method that returns to the chlorine route but uses electrochemistry to generate it catalytically from chloride (see the Perspective by Barton). This efficient process uses water in place of oxygen and can be integrated with the electrochemical generation of ethylene from carbon dioxide. Propylene oxide can be produced using the same method. Science, this issue p. 1228; see also p. 1181 The use of chloride as an electron shuttle enables efficient epoxide electrosynthesis from ethylene or propylene and water. Chemicals manufacturing consumes large amounts of energy and is responsible for a substantial portion of global carbon emissions. Electrochemical systems that produce the desired compounds by using renewable electricity offer a route to lower carbon emissions in the chemicals sector. Ethylene oxide is among the world’s most abundantly produced commodity chemicals because of its importance in the plastics industry, notably for manufacturing polyesters and polyethylene terephthalates. We applied an extended heterogeneous:homogeneous interface, using chloride as a redox mediator at the anode, to facilitate the selective partial oxidation of ethylene to ethylene oxide. We achieved current densities of 1 ampere per square centimeter, Faradaic efficiencies of ~70%, and product specificities of ~97%. When run at 300 milliamperes per square centimeter for 100 hours, the system maintained a 71(±1)% Faradaic efficiency throughout.

中文翻译：

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在高电流密度下氯化物介导的环氧乙烷和环氧丙烷的选择性电合成

加入环氧化物 环氧乙烷是一种应变的反应性分子，作为塑料前体大规模生产。目前的合成方法涉及乙烯和氧气在高温下的直接反应，但最初的方案依赖于氯的还原来生产氯醇中间体。刘等人。报告了一种室温方法，该方法返回到氯路线，但使用电化学从氯化物催化生成它（参见 Barton 的观点）。这种有效的过程使用水代替氧气，并且可以与从二氧化碳电化学生成乙烯相结合。环氧丙烷可以使用相同的方法生产。科学，这个问题 p。1228; 另见第 1181 使用氯化物作为电子穿梭可以有效地从乙烯或丙烯和水电合成环氧化物。化学品制造消耗大量能源，占全球碳排放量的很大一部分。通过使用可再生电力生产所需化合物的电化学系统为降低化学品行业的碳排放提供了一条途径。环氧乙烷是世界上产量最丰富的商品化学品之一，因为它在塑料工业中很重要，特别是用于制造聚酯和聚对苯二甲酸乙二醇酯。我们应用了扩展的异质：均质界面，在阳极使用氯化物作为氧化还原介质，以促进乙烯选择性部分氧化为环氧乙烷。我们实现了每平方厘米 1 安培的电流密度、~70% 的法拉第效率和~97% 的产品特性。当以每平方厘米 300 毫安的电流运行 100 小时时，系统始终保持 71(±1)% 的法拉第效率。