Kim Jiwon, Kim Jae Hyung, Oh Cheoulwoo, Yun Hyewon, Lee Eunchong, Oh Hyung-Suk, Park Jong Hyeok, Hwang Yun Jeong
Department of Chemical and Biomolecular Engineering, Yonsei-KIST Convergence Research Institute, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749, Republic of Korea.
Clean Energy Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seoul, 02792, Republic of Korea.
Nat Commun. 2023 Aug 5;14(1):4704. doi: 10.1038/s41467-023-40415-6.
Direct partial oxidation of methane to liquid oxygenates has been regarded as a potential route to valorize methane. However, CH activation usually requires a high temperature and pressure, which lowers the feasibility of the reaction. Here, we propose an electro-assisted approach for the partial oxidation of methane, using in-situ cathodically generated reactive oxygen species, at ambient temperature and pressure. Upon using acid-treated carbon as the electrocatalyst, the electro-assisted system enables the partial oxidation of methane in an acidic electrolyte to produce oxygenated liquid products. We also demonstrate a high production rate of oxygenates (18.9 μmol h) with selective HCOOH production. Mechanistic analysis reveals that reactive oxygen species such as ∙OH and ∙OOH radicals are produced and activate CH and CHOH. In addition, unstable CHOOH generated from methane partial oxidation can be additionally reduced to CHOH on the cathode, and so-produced CHOH is further oxidized to HCOOH, allowing selective methane partial oxidation.
甲烷直接部分氧化制液态含氧化合物被认为是甲烷增值的一条潜在途径。然而，甲烷活化通常需要高温高压，这降低了反应的可行性。在此，我们提出一种用于甲烷部分氧化的电辅助方法，即在常温常压下使用原位阴极产生的活性氧物种。使用酸处理的碳作为电催化剂时，该电辅助系统能够在酸性电解质中实现甲烷的部分氧化，以生产含氧化合物液体产物。我们还展示了含氧化合物的高产率（18.9 μmol h）以及甲酸的选择性生成。机理分析表明，会产生诸如∙OH和∙OOH自由基等活性氧物种，它们会活化甲烷和甲醇。此外，甲烷部分氧化产生的不稳定的甲酰氧基可在阴极上进一步还原为甲醇，如此生成的甲醇会进一步氧化为甲酸，从而实现甲烷的选择性部分氧化。
