Boutin Etienne, Wang Min, Lin John C, Mesnage Matthieu, Mendoza Daniela, Lassalle-Kaiser Benedikt, Hahn Christopher, Jaramillo Thomas F, Robert Marc
Université de Paris, Laboratoire d'Electrochimie Moléculaire, CNRS, 75013, Paris, France.
SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA.
Angew Chem Int Ed Engl. 2019 Nov 4;58(45):16172-16176. doi: 10.1002/anie.201909257. Epub 2019 Sep 25.
Conversion of CO into valuable molecules is a field of intensive investigation with the aim of developing scalable technologies for making fuels using renewable energy sources. While electrochemical reduction into CO and formate are approaching industrial maturity, a current challenge is obtaining more reduced products like methanol. However, literature on the matter is scarce, and even more for the use of molecular catalysts. Here, we demonstrate that cobalt phthalocyanine, a well-known catalyst for the electrochemical conversion of CO to CO, can also catalyze the reaction from CO or CO to methanol in aqueous electrolytes at ambient conditions of temperature and pressure. The studies identify formaldehyde as a key intermediate and an unexpected pH effect on selectivity. This paves the way for establishing a sequential process where CO is first converted to CO which is subsequently used as a reactant to produce methanol. Under ideal conditions, the reaction shows a global Faradaic efficiency of 19.5 % and chemical selectivity of 7.5 %.
将一氧化碳转化为有价值的分子是一个深入研究的领域，其目的是开发利用可再生能源制造燃料的可扩展技术。虽然电化学还原一氧化碳和甲酸盐已接近工业成熟水平，但目前的一个挑战是获得更多还原产物，如甲醇。然而，关于这一问题的文献很少，使用分子催化剂的情况更是如此。在这里，我们证明了钴酞菁，一种用于电化学将一氧化碳转化为二氧化碳的著名催化剂，在常温常压的水性电解质中，也能催化一氧化碳或二氧化碳转化为甲醇的反应。研究确定甲醛是关键中间体，并发现了一个意想不到的pH对选择性的影响。这为建立一个连续过程铺平了道路，在该过程中，一氧化碳首先转化为二氧化碳，随后二氧化碳用作反应物来生产甲醇。在理想条件下，该反应的整体法拉第效率为19.5%，化学选择性为7.5%。
