Ligand‐Protected Au55 with a Novel Structure and Remarkable CO2 Electroreduction Performance

• Published in: Angewandte Chemie International Edition Vol. 60; no. 38; pp. 20748 - 20753
• Main Authors: Wan, Xian‐Kai, Wang, Jia‐Qi, Wang, Quan‐Ming
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 13.09.2021
• Edition: International ed. in English
• Subjects: Absorption spectra; Au55; Carbon dioxide; Catalytic activity; Chemical reduction; Clusters; CO2 electroreduction; Direct reduction; Electrochemistry; Energy gap; Gold; ligand-protected nanocluster; Nanoclusters; optical properties; Phosphine; Phosphines; Selectivity
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202108207

A Au55 nanocluster with the composition of [Au55(p‐MBT)24(Ph3P)6](SbF6)3 (p‐MBT=4‐methylbenzenethiolate) is synthesized via direct reduction of gold‐phosphine and gold‐thiolate precursors. Single‐crystal X‐ray diffraction reveals that this Au55 nanocluster features a face‐centered cubic (fcc) Au55 kernel, different from the well‐known two‐shell cuboctahedral arrangement in Au55(Ph3P)12Cl6. The Au55 cluster shows a wide optical absorption band with optical energy gap (Eg=1.28 eV). It is found that the exclusion of chloride is crucial for the formation of the title cluster, otherwise rod‐like [Au25(SR)5(PPh3)10Cl2]2+ is obtained. The strategy to run synthetic reaction in the absence of halide leads to new members of phosphine/thiolate co‐protected metal nanoclusters. The Au55 nanocluster exhibits high catalytic activity and selectivity for electrochemical reduction of CO2 to CO; the Faradaic efficiency (FE) reaches 94.1 % at −0.6 V vs. reversible hydrogen electrode (RHE). The gold nanocluster [Au55(p‐MBT)24(Ph3P)6](SbF6)3 (p‐MBT=4‐methylbenzenethiolate) features a face‐centered cubic Au55 kernel. This cluster exhibits high catalytic activity and selectivity for electrochemical reduction of CO2 to CO, and the Faradaic efficiency (FE) reaches 94.1 % at −0.6 V. The exclusion of chloride is an effective strategy to generate new members of ligand‐protected metal nanoclusters.