We report selective electrocatalytic reduction of carbon dioxide (CO2) to carbon monoxide (CO) on gold (Au) nanoparticles (NPs) in 0.5 M KHCO3 at 25?. Among monodisperse 4-, 6-, 8-, and 10-nm NPs tested, the 8 nm Au NPs show the maximum Faradaic efficiency (FE) (up to 90% at -0.67 V vs. reversible hydrogen electrode, RHE). Density functional theory (DFT) calculations and further studies on catalysis in a matrix of butyl-3-methylimidazolium hexafluorophosphate  suggest that the presence of dominant edge sites over corner sites on the Au NP surface facilitates the stabilization of the reduction intermediates, such as COOH*, and the formation of CO. This mechanism is further supported by the fact that Au nanowires exhibited even higher reaction activity. The work demonstrates the great potentials of using monodisperse Au NPs and nanowires to optimize the available reaction intermediate binding sites for efficient and selective electrocatalytic reduction of CO2 to CO.

Monodisperse Au nanoparticles for selective electrocatalytic reduction of carbon dioxide

248th National Meeting (2014)

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