Body-Centered-Cubic-Kernelled Ag15Cu6 Nanocluster with Alkynyl Protection: Synthesis, Total Structure, and CO2 Electroreduction

Guocheng Deng; Jimin Kim; Megalamane S Bootharaju; Fang Sun; Kangjae Lee; Qing Tang; Yun Jeong Hwang; Taeghwan Hyeon

doi:10.1021/jacs.2c10338

Body-Centered-Cubic-Kernelled Ag₁₅Cu₆ Nanocluster with Alkynyl Protection: Synthesis, Total Structure, and CO₂ Electroreduction

J Am Chem Soc. 2023 Feb 15;145(6):3401-3407. doi: 10.1021/jacs.2c10338. Epub 2022 Dec 21.

Authors

Guocheng Deng^{1

2}, Jimin Kim^{1

3}, Megalamane S Bootharaju^{1

2}, Fang Sun⁴, Kangjae Lee^{1

2}, Qing Tang⁴, Yun Jeong Hwang^{1

3}, Taeghwan Hyeon^{1

2}

Affiliations

¹ Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.
² School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea.
³ Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea.
⁴ School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.

PMID: 36541445
DOI: 10.1021/jacs.2c10338

Abstract

While atomically monodisperse nanostructured materials are highly desirable to unravel the size- and structure-catalysis relationships, their controlled synthesis and the atomic-level structure determination pose challenges. Particularly, copper-containing atomically precise alloy nanoclusters are potential catalyst candidates for the electrochemical CO₂ reduction reaction (eCO₂RR) due to high abundance and tunable catalytic activity of copper. Herein, we report the synthesis and total structure of an alkynyl-protected 21-atom AgCu alloy nanocluster [Ag₁₅Cu₆(C≡CR)₁₈(DPPE)₂]^-, denoted as Ag₁₅Cu₆ (HC≡CR: 3,5-bis(trifluoromethyl)phenylacetylene; DPPE: 1,2-bis(diphenylphosphino)ethane). The single-crystal X-ray diffraction reveals that Ag₁₅Cu₆ consists of an Ag₁₁Cu₄ metal core exhibiting a body-centered cubic (bcc) structure, which is capped by 2 Cu atoms, 2 Ag₂DPPE motifs, and 18 alkynyl ligands. Interestingly, the Ag₁₅Cu₆ cluster exhibits excellent catalytic activity for eCO₂RR with a CO faradaic efficiency (FE_CO) of 91.3% at -0.81 V (vs the reversible hydrogen electrode, RHE), which is much higher than that (FE_CO: 48.5% at -0.89 V vs RHE) of Ag₉Cu₆ with bcc structure. Furthermore, Ag₁₅Cu₆ shows superior stability with no significant decay in the current density and FE_CO during a long-term operation of 145 h. Density functional theory calculations reveal that the de-ligated Ag₁₅Cu₆ cluster can expose more space at the pair of AgCu dual metals as the efficient active sites for CO formation.