Electro-assisted methane oxidation to formic acid via in-situ cathodically generated H2O2 under ambient conditions
Jiwon Kim, Jae Hyung Kim, Cheoulwoo Oh, Hyewon Yun, Eunchong Lee, Hyung‐Suk Oh, Jong Hyeok Park, Yun Jeong Hwang
Abstract
Abstract Direct partial oxidation of methane to liquid oxygenates has been regarded as a potential route to valorize methane. However, CH 4 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 −1 ) with selective HCOOH production. Mechanistic analysis reveals that reactive oxygen species such as ∙OH and ∙OOH radicals are produced and activate CH 4 and CH 3 OH. In addition, unstable CH 3 OOH generated from methane partial oxidation can be additionally reduced to CH 3 OH on the cathode, and so-produced CH 3 OH is further oxidized to HCOOH, allowing selective methane partial oxidation.