Ethanol is an important bulk chemical and alternative fuel that is currently synthesized by catalytic hydration of ethylene or fermentation of foods. CO₂ is a cheap and renewable carbon resource. Transformation of CO₂ into useful chemicals is an interesting topic in green chemistry. Production of ethanol using CO₂ and H₂ is a promising route, but the efficiency of the reaction is not satisfactory. In this paper, we propose a protocol to synthesize ethanol from paraformaldehyde, CO₂ and H₂. The reaction could be efficiently accelerated by a Ru–Co bimetallic catalyst using LiI as the promoter in 1,3-dimethyl-2-imidazolidinone (DMI) under mild conditions. The selectivity of ethanol in total products reached 50.9 C-mol%, which was obviously higher than that of the reported routes. Furthermore, the TOF of ethanol based on Ru metal was as high as 17.9 h⁻¹. To our knowledge, this is the first report on ethanol synthesis from paraformaldehyde, CO₂ and H₂. A detailed study indicated that the outstanding results of the reaction originated from the synergy of paraformaldehyde hydrogenation, reverse water gas shift reaction and methanol homologation.

中文翻译：

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由多聚甲醛，CO ₂和H ₂合成乙醇

乙醇是重要的散装化学燃料和替代燃料，目前是通过乙烯的催化水合或食品发酵合成的。CO ₂是一种廉价的可再生碳资源。将CO ₂转化为有用的化学物质是绿色化学中一个有趣的话题。使用CO ₂和H ₂生产乙醇是一种有前途的途径，但是反应效率不令人满意。在本文中，我们提出了一种从多聚甲醛，CO ₂和H ₂合成乙醇的方案。在温和的条件下，使用LiI作为促进剂的Ru-Co双金属催化剂可以有效地促进反应，在1,3-二甲基-2-咪唑啉酮（DMI）中。乙醇在总产物中的选择性达到50.9 C-mol％，明显高于所报道的路线。此外，基于Ru金属的乙醇的TOF高达17.9h ^-1。据我们所知，这是关于从多聚甲醛，CO ₂和H ₂合成乙醇的第一份报告。详尽的研究表明，该反应的杰出结果源自多聚甲醛加氢，反向水煤气变换反应和甲醇同系化的协同作用。