Robust Gold Nanocluster Protected with Amidinates for Electrocatalytic CO2 Reduction

• Published in: Angewandte Chemie International Edition Vol. 60; no. 26; pp. 14345 - 14349
• Main Authors: Yuan, Shang‐Fu, He, Rui‐Lin, Han, Xu‐Shuang, Wang, Jia‐Qi, Guan, Zong‐Jie, Wang, Quan‐Ming
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 21.06.2021
• Edition: International ed. in English
• Subjects: amidinate ligands; Carbon dioxide; Catalysts; Core-shell structure; Crystal structure; electrocatalytic CO2RR; geometric closure; Gold; gold nanocluster; Ligands; Nanoclusters; Robustness; Shells; Single crystals; thermal stability; electronic shell closure; thermal stability; gold nanocluster; amidinate ligands; geometric closure
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202103060

The first all‐amidinate‐protected gold nanocluster [Au28(Ph−form)12](OTf)2 (Ph‐form=N,N′‐diphenylformamidinate) (Au28) has been synthesized and structurally resolved. Single crystal X‐ray diffraction reveals that Au28 has a compact Au4@Au24 tetrahedral core–shell structure of T symmetry, which is fully protected by 12 bridging formamidinate ligands. This cluster is quite robust as indicated by the fact that it can stay intact in solution at 80 °C for 6 d. It exhibits excellent catalytic performance for the electroreduction of CO2 with 96.5 % Faradaic efficiency (FE) at −0.57 V and a maximum TOF of 1731 h−1 at −0.87 V. Its superior stability is also manifested in the fact that the supported catalyst Au28/CNTs maintains stable potentials at ca. −0.69 V for 40 h with FE(CO)s>91 %. A superatomic electron configuration of 1S21P62S21D4 has been clarified by DFT computations, and the strong gold–ligand binding and geometric shell closure account for the superior stability of Au28. The first all‐amidinate‐supported gold nanocluster Au28 has been synthesized and structurally resolved. This cluster is quite robust manifested by the fact that it can stay intact in solution at 80 °C for 6 d and maintain high FE(CO)s and activity over 40 hour operation for electroreduction of CO2. The strong gold–ligand binding and geometric closure account for the superior stability of Au28.