Banerjee Aanindeeta, Kanan Matthew W
Department of Chemistry, Stanford University, Stanford, California 94305, United States.
ACS Cent Sci. 2018 May 23;4(5):606-613. doi: 10.1021/acscentsci.8b00108. Epub 2018 Apr 30.
CO hydrogenation is a potential alternative to conventional petrochemical methods for making commodity chemicals and fuels. Research in this area has focused mostly on transition-metal-based catalysts. Here we show that hydrated alkali carbonates promote CO hydrogenation to formate, oxalate, and other C carboxylates at elevated temperature and pressure in the absence of transition-metal catalysts or solvent. The reactions proceed rapidly, reaching up to 56% yield (with respect to CO) within minutes. Isotope labeling experiments indicate facile H and C-H deprotonations in the alkali cation-rich reaction media and identify probable intermediates for the C-C bond formations leading to the various C products. The carboxylate salts are in equilibrium with volatile carboxylic acids under CO hydrogenation conditions, which may enable catalytic carboxylic acid syntheses. Our results provide a foundation for base-promoted and base-catalyzed CO hydrogenation processes that could complement existing approaches.
一氧化碳加氢是一种有潜力的替代传统石化方法来生产商品化学品和燃料的途径。该领域的研究主要集中在过渡金属基催化剂上。在此我们表明，在不存在过渡金属催化剂或溶剂的情况下，水合碱金属碳酸盐在高温高压下能促进一氧化碳加氢生成甲酸盐、草酸盐和其他羧酸盐。反应迅速进行，几分钟内产率（相对于一氧化碳）可达56%。同位素标记实验表明，在富含碱金属阳离子的反应介质中，氢和碳 - 氢键的去质子化过程很容易发生，并确定了导致各种碳产物的碳 - 碳键形成的可能中间体。在一氧化碳加氢条件下，羧酸盐与挥发性羧酸处于平衡状态，这可能实现催化羧酸合成。我们的结果为碱促进和碱催化的一氧化碳加氢过程提供了基础，可补充现有方法。
