Chen Yuanjun, Li Xiao-Yan, Chen Zhu, Ozden Adnan, Huang Jianan Erick, Ou Pengfei, Dong Juncai, Zhang Jinqiang, Tian Cong, Lee Byoung-Hoon, Wang Xinyue, Liu Shijie, Qu Qingyun, Wang Sasa, Xu Yi, Miao Rui Kai, Zhao Yong, Liu Yanjiang, Qiu Chenyue, Abed Jehad, Liu Hengzhou, Shin Heejong, Wang Dingsheng, Li Yadong, Sinton David, Sargent Edward H
Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.
Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.
Nat Nanotechnol. 2024 Mar;19(3):311-318. doi: 10.1038/s41565-023-01543-8. Epub 2023 Nov 23.
The electrochemical reduction of CO in acidic conditions enables high single-pass carbon efficiency. However, the competing hydrogen evolution reaction reduces selectivity in the electrochemical reduction of CO, a reaction in which the formation of CO, and its ensuing coupling, are each essential to achieving multicarbon (C) product formation. These two reactions rely on distinct catalyst properties that are difficult to achieve in a single catalyst. Here we report decoupling the CO-to-C reaction into two steps, CO-to-CO and CO-to-C, by deploying two distinct catalyst layers operating in tandem to achieve the desired transformation. The first catalyst, atomically dispersed cobalt phthalocyanine, reduces CO to CO with high selectivity. This process increases local CO availability to enhance the C-C coupling step implemented on the second catalyst layer, which is a Cu nanocatalyst with a Cu-ionomer interface. The optimized tandem electrodes achieve 61% CH Faradaic efficiency and 82% C Faradaic efficiency at 800 mA cm at 25 °C. When optimized for single-pass utilization, the system reaches a single-pass carbon efficiency of 90 ± 3%, simultaneous with 55 ± 3% CH Faradaic efficiency and a total C Faradaic efficiency of 76 ± 2%, at 800 mA cm with a CO flow rate of 2 ml min.
在酸性条件下对CO进行电化学还原可实现较高的单程碳效率。然而，竞争性析氢反应降低了CO电化学还原的选择性，在该反应中，CO的形成及其随后的偶联对于实现多碳（C）产物形成均至关重要。这两个反应依赖于单一催化剂难以具备的不同催化剂特性。在此，我们报告通过串联操作两个不同的催化剂层，将CO到C的反应解耦为两个步骤，即CO到CO和CO到C，以实现所需的转化。第一种催化剂是原子分散的钴酞菁，它能以高选择性将CO还原为CO。这一过程增加了局部CO的可用性，以增强在第二个催化剂层上进行的C-C偶联步骤，第二个催化剂层是具有铜离聚物界面的铜纳米催化剂。优化后的串联电极在25°C、800 mA cm²条件下实现了61%的CH法拉第效率和82%的C法拉第效率。当针对单程利用率进行优化时，该系统在800 mA cm²、CO流速为2 ml min⁻¹的条件下，单程碳效率达到90±3%，同时CH法拉第效率为55±3%，总C法拉第效率为76±2%。
