Figure 4.

a) Potential‐dependent Faradaic efficiencies of different Au NPs (4, 6, 8, 10 nm) during electrocatalytic reduction of CO₂ to CO. b) Current densities (mass activity) for electrocatalytic reduction of CO₂ to CO on the Au NPs with different sizes at various applied potentials. Free energy diagrams for electrochemical reduction of c) CO₂ to CO and d) protons to hydrogen on Au (111), Au (211), and a 13‐atom Au cluster at −0.11 V (vs RHE), respectively. Reproduced with permission.79 Copyright 2013, American Chemical Society. Free energy diagrams for electrochemical reduction of e) CO₂ to CO and f) H⁺ to H₂ on Au(111), Au(211), Au₅₅ NPs, and Au₃₈ NPs at 0 V versus RHE. Reproduced with permission.80 Copyright 2014, American Chemical Society. g) Morphological model of concave rhombic dodecahedron Au NPs with different exposed facets. h) Faradaic efficiencies of different Au NPs and Au film for CO production at applied potential (vs RHE). Reproduced with permission.81 Copyright 2015, American Chemical Society.