Breaking the activity limitation of iridium single-atom catalyst in hydrogenation of quinoline with synergistic nanoparticles catalysis

• Published in: Nano research Vol. 15; no. 6; pp. 5024 - 5031
• Main Authors: Shen, Qikai, Jin, Hongqiang, Li, Peipei, Yu, Xiaohu, Zheng, Lirong, Song, Weiguo, Cao, Changyan
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.06.2022
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Catalysis; Catalysts; Catalytic activity; Chemical bonds; Chemistry and Materials Science; Condensed Matter Physics; Density functional theory; Hydrogenation; Iridium; Materials Science; Nanoparticles; Nanotechnology; Quinoline; Research Article; Single atom catalysts; synergistic; quinoline; heterogeneous catalysis; hydrogenation; single atom
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-022-4235-4

Single-atom catalysts (SACs) with the advantages of homogeneous and heterogeneous catalysts have become a hot-spot in catalysis field. However, for lack of metal-metal bond in SACs, H 2 has to go through heterolytic dissociation pathway, which has higher barrier than homolytic dissociation pathway, and thus limits the hydrogenation activity of SACs. Herein, we propose and demonstrate through constructing synergistic iridium single atoms and nanoparticles co-existed catalyst (denoted as Ir 1+NPs /CMK) to boost the catalytic activity of quinoline hydrogenation. Both experimental and density functional theory calculation results confirm that Ir 1 single sites activate quinoline, while Ir nanoparticles boost hydrogen dissociation. H atoms generated at Ir nanoparticles migrate to the quinoline bounded Ir 1 single sites to complete hydrogenation. The Ir 1+NPs /CMK catalyst exhibits much higher reactivity with turnover frequency of 7,800 h −1 than those counterpart Ir 1 /CMK and Ir NPs /CMK catalysts, and is 20,000 times higher activity of commercial Ir/C benchmark catalyst for hydrogenation of quinoline under the same reaction conditions. This synergistic catalysis strategy between single atoms and nanoparticles provides a solution to further improve the performance of SACs for hydrogenation.