清华大学李亚栋团队报道了工业条件下CO₂介导的有机催化氯析出。相关研究成果于2023年5月17日发表于国际一流学术期刊《自然》。

氯碱加工自19世纪以来一直在运行，氯化钠溶液的电解产生氯和氢氧化钠，这两种物质对化学制造都很重要。由于这一过程非常耗能，全球4%的电力（约150TWh）流向氯碱行业，即使是适度的效率提高也可以带来可观的成本和能源节约。这方面的一个特别关注点是要求苛刻的析氯反应，为此，最先进的电催化剂仍然是几十年前开发的尺寸稳定的阳极。已经报道了用于析氯反应的新催化剂，但它们仍然主要由贵金属组成。

该文中，研究表明具有酰胺官能团的有机催化剂能够进行析氯反应；并且在CO₂存在的情况下，它在仅89mV的过电位下实现了10kAm^-2的电流密度和99.6%的选择性，从而与尺寸稳定的阳极相媲美。研究发现，CO₂与酰胺氮的可逆结合促进了自由基物种的形成，该自由基物种在Cl₂的生成中起着关键作用，这也可能被证明在Cl电池和有机合成的背景下是有用的。尽管有机催化剂通常不被认为有希望用于要求苛刻的电化学应用，但这项工作证明了它们具有更广泛的潜力，以及它们为开发与工业相关的新工艺和探索新的电化学机制提供的机会。

附：英文原文

Title: CO2-mediated organocatalytic chlorine evolution under industrial conditions

Author: Yang, Jiarui, Li, Wen-Hao, Tang, Hai-Tao, Pan, Ying-Ming, Wang, Dingsheng, Li, Yadong

Issue&Volume: 2023-05-17

Abstract: During the chlor-alkali process, in operation since the nineteenth century, electrolysis of sodium chloride solutions generates chlorine and sodium hydroxide that are both important for chemical manufacturing1,2,3,4. As the process is very energy intensive, with 4% of globally produced electricity (about 150TWh) going to the chlor-alkali industry5,6,7,8, even modest efficiency improvements can deliver substantial cost and energy savings. A particular focus in this regard is the demanding chlorine evolution reaction, for which the state-of-the-art electrocatalyst is still the dimensionally stable anode developed decades ago9,10,11. New catalysts for the chlorine evolution reaction have been reported12,13, but they still mainly consist of noble metal14,15,16,17,18. Here we show that an organocatalyst with an amide functional group enables the chlorine evolution reaction; and that in the presence of CO2, it achieves a current density of 10kAm2 and a selectivity of 99.6% at an overpotential of only 89mV and thus rivals the dimensionally stable anode. We find that reversible binding of CO2 to the amide nitrogen facilitates formation of a radical species that plays a critical role in Cl2 generation, and that might also prove useful in the context of Cl batteries and organic synthesis19,20,21. Although organocatalysts are typically not considered promising for demanding electrochemical applications, this work demonstrates their broader potential and the opportunities they offer for developing industrially relevant new processes and exploring new electrochemical mechanisms.

DOI: 10.1038/s41586-023-05886-z

Source: https://www.nature.com/articles/s41586-023-05886-z