Selective formation of ketones by electrochemical reduction of CO2 catalyzed by ruthenium complexes

Abstract

Electrochemical reduction of CO 2 aimed at carbon-carbon bond formation was examined. Polypyridyl-ruthenium-carbonyl complexes catalyze electrochemical reduction of CO 2 to produce CO and CO 3 2À in organic solvents. Among those metal complexes, a ruthenium carbonyl complex with monodentate naphthyridine showed a unique redox behavior. Oneelectron reduction of the complex resulted in intramolecular nucleophilic attack of the nonbonded nitrogen of naphthyridine to the carbonyl carbon to form a five-membered ring. Such metallacyclization greatly served for activation of the Ru-CO bond derived from CO 2 without accompanying reductive cleavage of the bond (CO evolution). Electrochemical reduction of CO 2 catalyzed by [Ru(bpy)(napy) 2 (CO) 2 ] 2 in the presence of (CH 3 ) 4 NBF 4 produced only CH 3 C(O)CH 3 and CO 3 2À , where (CH 3 ) 4 N worked as not only the electrolyte but also the methylation reagent.

Reactions of [Ru(CO)3Cl2]2 with aromatic nitrogen donor ligands in alcoholic media

“…11,12 Catalytic applications of these complexes include, for example, epoxidation of cyclohexene, 13 cyclopropanation of styrene, 14 water gas shift reaction 15 and carbon dioxide reduction. 16,17 A more recent application of these compounds is as nitric oxide (NO − ) radical releasers that could participate in biological processes like modulation of immune and endocrine response. 18,19 Materials, Nanoscience and Catalysis Scheme 1.…”

Effect of PDI ligand binding pattern on the electrocatalytic activity of two Ru(II) complexes for CO2 reduction

“…Molecular catalysts based on ruthenium transition metal complexes for electrochemical reduction of CO 2 have attracted considerable research attention due to their unique structural and electronic features, as well as, homogeneous complexes retaining the advantages of elucidating catalytic processes for optimizing the catalysts. [9,10] A great many remarkable achievements have been reported by Meyer, [11][12][13] Kubiak, [10] Tanaka, [14][15][16][17][18][19] Fujita, [20][21][22] Miller, [1] Huang, [23] and others. [24][25][26][27] However, because of the exceptional thermodynamic stability of CO 2 and the multiple electrons required in the reaction process, many ruthenium catalysts have low efficiency and selectivity.…”

Fixation of CO2 by Electrocatalytic Reduction and Electropolymerization in Ionic Liquid–H2O Solution

“…The direct electrochemical reduction products of CO 2 reported to date include methane, methanol, ethanol, formaldehyde, formic, oxalic and lactic acid, and malate. [11][12][13][14][15][16][17][18][29][30][31][32][33][34][35] However, we are not aware of any other reports on the direct electrochemical synthesis of complex organic compounds from CO 2 . We report here for the first time the electrocatalytic synthesis of low-density polyethylene from CO 2 on a nanostructured (ns)TiO 2 film electrode by controlled potential electrolysis in [EMI]BF 4 -H 2 O at ambient temperature and pressure.…”