Direct Conversion of Methanol to Ethanol on the Metal‐Carbon Interface

Abstract

Direct conversion of one-carbon (C 1 ) compounds to two-carbon (C 2 ) and multi-carbon compounds remains a critical challenge for converting non-petroleum resources to valuable chemicals or fuels. The key issue is the selective activation of C 1 compounds, methanol, as well as the controlled formation of carbon-carbon (CÀ C) bonds. Herein, we achieve the direct electrocatalytic methanol to ethanol, an important chemical and energy candidate, with methanol conversion, ethanol selectivity, and faradic efficiency of 257.0 g · m À 2 · h À 1 , 95.1 %, and 12.5 %, respectively. Furthermore, the appropriate participation of water, as a by-product from methanol electrocatalysis, in hydrogen evolution reaction (HER) facilitates electrocatalytic reaction of methanol. Mechanistic studies reveal hydroxymethyl and methyl radicals are formed on the electropositive low-valent metal sites and electronegative carbon vacancies, respectively, and then combined with each other to form ethanol at the metal/carbon interface. This work opens a unique route for high-efficient concerted redox conversion of methanol reactant to ethanol. . In situ ESR spectra of electrocatalytic reaction systems in TCR in the presence of DMPO with or without electricity. a) Electrochemical reaction conditions were a N 2 -saturated solution of 0.147 g NaCl in 25 mL methanol containing Co 3 ZnC/NC catalyst with DMPO (cathode chamber) and that of 25 mL 0.5 M aqueous Na 2 SO 4 (anode chamber). Characterization conditions were microwave frequency of 9.44 GHz, microwave power of 20 mW, modulation frequency of 100.00 kHz; b) Reaction and characterization conditions were consistent with a) except for no addition of electricity; c) Related conditions were consistent with b except for no addition of DMPO in cathode chamber. Figure 4. Schematic illustration of Co 3 ZnC/NC catalyst for direct electrocatalytic conversion of methanol to ethanol and the plausible reaction mechanism.

Tunable Generation of Reactive Oxygen Species in SnO2/SnS2 Nanostructures: Mechanistic Insights into Indigo Carmine Photodegradation

“…When methanol is introduced into the solution (Figure b), a distinct signal appears instead of the previously observed • OH adducts. Computer simulation of this spectrum revealed that it can be decomposed into two separate signals originating from the DMPO-OOH ( A N = 1.418 mT, A H1 = 0.942 mT, A H2 = 0.150 mT) and the DMPO–CH 2 OH adducts , ( A N = 1.560 mT, A H1 = 2.197 mT).…”

“…Computer simulation of this spectrum revealed that it can be decomposed into two separate signals originating from the DMPO-OOH 52 (A N = 1.418 mT, A H1 = 0.942 mT, A H2 = 0.150 mT) and the DMPO−CH 2 OH adducts 55,56 (A N = 1.560 mT, A H1 = 2.197 mT).…”

Selective Transformation of Methanol to Ethanol in the Presence of Syngas over Composite Catalysts

“…Hydrocarbon fuels and value-added chemicals, including lower olefins, aromatics, and oxygenates, can be produced from methanol via C–C coupling reactions. − Compared to the methanol to hydrocarbon transformation, the synthesis of ethanol from methanol by precise C–C coupling is highly attractive and atomically economical because of the presence of oxygen in the product. Thermodynamic analyses reveal that the direct conversion of methanol to ethanol and H 2 O (2CH 3 OH → C 2 H 5 OH + H 2 O) is thermodynamically feasible (Figure S1a) but the activation of C–H and C–O bonds in methanol and the precise coupling of suitable intermediates to form ethanol remains highly challenging . Few studies have been devoted to direct conversion of methanol into ethanol by photocatalysis (Figure , Route A) and electrocatalysis (Figure , Route B) routes. , However, these processes suffered from very low yields of ethanol (<2%), which are far from satisfactory.…”

“…Thermodynamic analyses reveal that the direct conversion of methanol to ethanol and H 2 O (2CH 3 OH → C 2 H 5 OH + H 2 O) is thermodynamically feasible (Figure S1a) but the activation of C–H and C–O bonds in methanol and the precise coupling of suitable intermediates to form ethanol remains highly challenging . Few studies have been devoted to direct conversion of methanol into ethanol by photocatalysis (Figure , Route A) and electrocatalysis (Figure , Route B) routes. , However, these processes suffered from very low yields of ethanol (<2%), which are far from satisfactory.…”

“…13 Few studies have been devoted to direct conversion of methanol into ethanol by photocatalysis (Figure 1, Route A) and electrocatalysis (Figure 1, Route B) routes. 13,14 However, these processes suffered from very low yields of ethanol (<2%), which are far from satisfactory.…”