Method for Electrocatalytic Reduction using Au Nanoparticles Tuned or Optimized for Reduction of CO2 to CO

摘要

Selective electrocatalytic reduction of carbon dioxide (CO2) to carbon monoxide (CO) on gold (Au) nanoparticles (NPs) in 0.5 M KHCO3 at 25° C. 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. Density functional theory (DFT) calculations suggest that edge sites dominate over corner sites on the Au NP surface facilitating stabilization of the reduction intermediates, such as COOH1*, and the formation of CO. This mechanism is further supported by the fact that Au NPs embedded in a matrix of butyl-3methylimidazolium hexafluorophosphate for more efficient COOH* stabilization exhibit even higher reaction activity (3 A/g mass activity) and selectivity (97% FE) at −0.52 V (vs. RHE). Use of monodisperse Au NPs to optimize the available reaction intermediate binding sites thus allows efficient and selective electrocatalytic reduction of CO2 to CO.

主权项

1. A process for electrocatalytic reduction of CO2 to CO wherein the reduction is Catalyzed by gold nanoparticles on a conductive support, and the nanoparticles are sized to present a crystalline structure that achieves a stable and efficient reduction.