Highly selective electrochemical oxidation of 2-nitro-4-methylsulfonyltoluene to 2-nitro-4-methylsulfonylbenzoic acid enabled by molybdate

Minireview of Coupled Electrochemical Hydrogen Production and Organic-Oxidation for Low Energy Consumption

“…In addition, Fu et al coupled HER with electro-oxidation of 2nitro-4-methylsulfonyltoluene (NMSBA) to 2-nitro-4-methylsulfonylbenzoic acid (NMST). 71 In this study, a commercial graphite rod and a platinum plate were used as the anode and cathode, respectively (Figure 12). Several redox mediators, such as Ni 2+ , Mn 2+ , Ce 3+ , Co 2+ employed in the electrochemical oxidation of NMST in 2 M H 2 SO 4 .…”

“…The oxygenation of C�C and C−H is more difficult, and only few organics containing these groups can be electro-oxidized into epoxides 70 or corresponding carboxylic acids with relatively low selectivities. 71 In contrast, electro-oxidation of alcohols has been widely used to combine with HER for H 2 production, where aldehydes are usually the intermediate products during the alcohol oxidation, and are thus more easily to be oxidized further into the corresponding acids or even into CO 2 (Figure 13). Therefore, for most alcohols, the corresponding acids will be generated finally, attributing to the small energy barrier between aldehydes/ketones and acids 72,73 and the large barrier between acids and CO 2 .…”

“…In addition, Fu et al coupled HER with electro-oxidation of 2-nitro-4-methylsulfonyltoluene (NMSBA) to 2-nitro-4-methylsulfonylbenzoic acid (NMST) . In this study, a commercial graphite rod and a platinum plate were used as the anode and cathode, respectively (Figure ).…”

“…(b) Catalyst screening for electrochemical oxidation of NMST at 20 °C for 6 h. Operating conditions: H 2 SO 4 : 2 M; Voltage: 2.2 V; NMST: 0.02 M; catalyst: 0.1 M; PTC: 0.12 wt %. Reproduced with permission from ref , Copyright 2022, Springer.…”

“…On the basis of the above analysis, the oxygenation process usually happens during the electro-oxidation of alcohols (C–OH), aldehydes or ketones (CHO or CO), and CC/C–H. The oxygenation of CC and C–H is more difficult, and only few organics containing these groups can be electro-oxidized into epoxides or corresponding carboxylic acids with relatively low selectivities . In contrast, electro-oxidation of alcohols has been widely used to combine with HER for H 2 production, where aldehydes are usually the intermediate products during the alcohol oxidation, and are thus more easily to be oxidized further into the corresponding acids or even into CO 2 (Figure ).…”