[AuAg₂₆(SR)₁₈S]⁻ Nanocluster: Open Shell Structure and High Faradaic Efficiency in Electrochemical Reduction of CO₂ to CO

Abstract

For atomically precise metal nanoclusters, distinctive molecular architectures and promising applications are urgently required to be intensively explored. Herein, we have first reported the open shell structure of the [AuAg 26 (S−Adm) 18 S] − nanocluster and its application in the electrochemical reduction of CO 2 . The X-ray crystal structure of the AuAg 26 nanocluster is composed of a AuAg 12 icosahedron kernel and a Ag 14 (SR) 18 S open shell. The shell includes a Ag 6 (SR) 3 S, a Ag 5 (SR) 6 , and three Ag(SR) 3 motifs. It is the first time twisty propeller-like Ag 5 (SR) 6 and trefoil-like Ag 6 (SR) 3 S motifs in metal nanoclusters have been observed. Due to the novel open shell configuration of Ag 14 (SR) 18 S, four triangular facets of the kernel are exposed. The AuAg 26 nanocluster shows excellent catalytic activity in the electrochemical reduction of CO 2 to CO. The Faradaic efficiency of CO is up to 98.4% under −0.97 V. The electrochemical in situ infrared study and DFT calculations demonstrate that the open shell structure of the AuAg 26 nanocluster is beneficial to the forming of intermediate COOH* in the electrochemical reduction of CO 2 to CO.

Homoleptic Alkynyl‐Protected Ag15 Nanocluster with Atomic Precision: Structural Analysis and Electrocatalytic Performance toward CO2 Reduction

“…The partial current density of CO and H 2 increased with the increasing of overpotential (Figure 4 b). At −0.9 V, the CO partial current density of the Ag 15 (C≡C‐ t Bu) 12 + catalyst reached 13.0 mA cm −2 in an aqueous H‐Cell reactor, which exceeds the performance of most recently reported cluster‐based catalysts [34, 41, 42] . The turnover frequency (TOF) of the Ag 15 NC was also calculated (Figure 4 c), where the maximal TOF value is 6.37 s −1 at −1.1 V. Stability is another important criterion to evaluate the electrocatalyst.…”

Heterometallation of Photoluminescent Silver(I) Sulfide Nanoclusters Protected by Octahedral Iridium(III) Thiolates

“…We assume that the preference of a linear coordination geometry for Cu I and Au I leads to the unique site‐specific heterometallation in [ 1 Cu ] 20+ and [ 1 Au ] 20+ to maintain the overall nanocluster covered by the fac ‐[Ir(aet) 3 ] metalloligands. It should be noted that these are very rare heterometallic sulfide nanoclusters with ordered heteroatoms in a definite composition [9b–d,10] …”

The Factors Dictating Properties of Atomically Precise Metal Nanocluster Electrocatalysts

“…[91] More recently, Huang et al successfully synthesized a gold atom alloyed with AuAg 26 NCs by a one-pot method. [92] Using a single-crystal X-ray diffraction technique, the precise structure of the cluster was determined as AuAg 26 and shows that it consists of an AuAg 12 icosahedral core and an Ag 14 (SR) 18 S shell, where Ag 6 (SR) 3 S, Ag 5 (SR) 6 , and three Ag(SR) 3 motifs are involved in the shell. Benefiting from the unique motifs, four triangular facets of the AuAg 12 core are exposed without passivation by ligands.…”

“…Due to the novel open shell configuration and synergistic effect between Au and Ag, the AuAg 26 NC demonstrates promising catalytic activity in the electrochemical CO 2 reduction with an optimized FE value of 98.4% at −0.97 V (versus RHE). [ 92 ]…”