Selective Production of Acetone in the Electrochemical Reduction of CO2 Catalyzed by a Ru-Naphthyridine Complex

Abstract

The controlled potential electrolysis of [Ru(bpy)(napy)2(CO)2](BF4)2 (1; bpy=2,2′-bipyridine, napy=1,8-naphthyridine) in the presence of LiBF4 in CO2-saturated DMSO at −1.65 V (vs. Ag/Ag+) produced CO and Li2CO3 [Eq. (a)], while similar electrolysis in the presence of (CH3)4NBF4 resulted in formation of acetone together with (CH3)3N and {(CH3)4N}2CO3 [Eq. (b)]. This represents the first almost selective generation of acetone upon electrochemical reduction of CO2. The selectivity is ascribed to depression of reductive cleavage of the Ru−CO bond of 1 due to an attack of the nonbonded nitrogen atom of napy at the carbonyl carbon atom.