Ultrathin Amorphous/Crystalline Heterophase Rh and Rh Alloy Nanosheets as Tandem Catalysts for Direct Indole Synthesis

• Published in: Advanced materials (Weinheim) Vol. 33; no. 9; pp. e2006711 - n/a
• Main Authors: Ge, Jingjie, Yin, Peiqun, Chen, Ye, Cheng, Hongfei, Liu, Jiawei, Chen, Bo, Tan, Chaoliang, Yin, Peng‐Fei, Zheng, Hong‐Xing, Li, Qiang‐Qiang, Chen, Shuangming, Xu, Wenjie, Wang, Xiaoqian, Wu, Geng, Sun, Rongbo, Shan, Xiang‐Huan, Hong, Xun, Zhang, Hua
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.03.2021
• Subjects: amorphous structures; Bimetals; Catalysis; Catalysts; Catalytic activity; Chemical synthesis; Crystal structure; Crystallinity; Fine chemicals; heterophases; indole synthesis; Materials science; Nanosheets; Rh and Rh alloys; Rhodium; Rhodium base alloys; Selectivity; tandem catalysis; ultrathin nanosheets; indole synthesis; ultrathin nanosheets; amorphous structures; Rh and Rh alloys; tandem catalysis; heterophases
• DOI: 10.1002/adma.202006711
• ISSN: 0935-9648; 1521-4095

Heterogeneous noble‐metal‐based catalysis plays an essential role in the production of fine chemicals. Rh‐based catalysts are one of the most active candidates for indole synthesis. However, it is still highly desired to develop heterogeneous Rh‐based catalysts with high activity and selectivity. In this work, a general, facile wet‐chemical method is reported to synthesize ultrathin amorphous/crystalline heterophase Rh and Rh‐based bimetallic alloy nanosheets (NSs), including RhCu, RhZn, and RhRu. Impressively, the amorphous/crystalline heterophase Rh NSs exhibit enhanced catalytic activity toward the direct synthesis of indole compared to the crystalline counterpart. Importantly, the obtained amorphous/crystalline heterophase RhCu alloy NSs can further enhance the selectivity to indole of >99.9% and the conversion is 100%. This work demonstrates the importance of phase engineering and metal alloying in the rational design and synthesis of tandem heterogeneous catalysts toward fine chemical synthesis. Ultrathin Rh and RhM (M = Cu, Zn, Ru) alloy nanosheets with amorphous/crystalline heterophases are successfully synthesized. In tandem catalysis to directly synthesize indole, the amorphous/crystalline heterophase Rh nanosheets (NSs) outperform their crystalline counterpart, demonstrating much higher catalytic activity. Impressively, the amorphous/crystalline heterophase RhCu NSs show dramatically enhanced indole selectivity of over 99.9% and excellent activity.