Electrochemical CO₂ Reduction on Bimetallic Surface Alloys: Enhanced Selectivity to CO for Co/Au(110) and to H₂ for Sn/Au(110)

Abstract

We investigated electrochemical CO2 reduction (ECR) on 0.1 monolayer‐thick‐Co and Sn‐deposited Au(110) surfaces (Co/Au(110), and Sn/Au(110)). Scanning tunneling microscopic images showed quasi‐one‐dimensional Co and Sn islands with different aspect ratios growing along the trenches of the missing‐row direction of the (1×2) reconstructed Au(110) surface. The selectivity and partial current density of the CO and H2 evolutions correlated with those of the deposited metals. CO evolution selectivity of the former Co/Au(110) increased compared with that of the Au(110), while that of the Sn/Au(110) significantly decreased. Co/Au(110) showed 1.4‐fold higher CO evolution activity than that of the clean Au(110) at −1.35 V vs. reversible hydrogen electrode. In contrast, the H2 evolution of the latter surface was significantly enhanced at a potential lower than −0.1 V. The results showed that site separations of Au and alloying elements of Co and Sn at the topmost surface determine the ECR product selectivity of alloy electrodes.

Composition sensitive selectivity and activity of electrochemical carbon dioxide reduction on Pd–Cu solid-solution alloy nanoparticles

“…This study cannot explain the origin of large difference in potential-dependent selectivity at only a 10% difference in composition. Elucidating this composition effect is challenging for nanostructured catalysts because the selectivity is also influenced by several factors including the surface atomic structures 12,13,53 and lattice strain. 54,55 Studies using model catalysts such as single-crystal electrodes with well-defined surface structures can be a potential tool for clarifying this issue.…”

“…The improvement of activity and selectivity for CO 2 RR electrocatalysts has been studied by various approaches, such as surface structure control, [11][12][13] halogen anion additions, 14,15 and surface modification by organic molecules. 7,16,17 In addition, alloying is an effective strategy to improve the CO 2 RR properties.…”

Surface modification of gold by carbazole dendrimers for improved carbon dioxide electroreduction

“…[2][3][4][5][6][7] Previous research has shown that Au, Ag, and Zn electrodes selectively convert CO 2 to CO. 8 In particular, Au showed relatively high efficiency for CO 2 reduction compared to that for hydrogen evolution, which is a competitive reaction of CO 2 reduction in aqueous solutions. [8][9][10] However, the activity and selectivity of the Au electrode for converting CO 2 to CO remain insufficient for widespread application, and further research on CO 2 electrolysis systems is necessary to attain industrialisation.…”

Boosting CO2 electroreduction over Co nanoparticles supported on N,B-co-doped graphitic carbon

“…To date, the main catalysts used in the electrocatalytic CO 2 RR of CO 2 to CO include noble metals (Au, Ag, and Pd), 13–15 oxides (CuO, ZnO, and Bi 2 O 3 ), 16–18 chalcogenides (Cu 2 S, CdS, and MoS 2 ), 19–21 alloys (Pd–Ag, Co–Au, and Cu–Ru), 22–24 single-atom catalysts 25–28 and some carbon materials. 29–31 These catalysis processes can efficiently hinder the hydrogen evolution reaction (HER), which is competitive with CO 2 RR.…”