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Abstract The rapid and environmentally benign synthesis of metal‐immobilized covalent organic frameworks (metal/COFs) for heterogeneous catalysis is a pervasive challenge, as the mainstream synthesis is exceedingly time‐consuming (up to four days) and demands the use of hazardous solvents. Herein, we describe a sustainable and efficient one‐step sonochemical strategy for constructing diverse palladium (II)‐immobilized COFs (Pd(II)/COFs). By merging the sonochemistry‐assisted COF synthesis and in situ Pd (II) immobilization into a single step, this strategy enables the rapid formation of Pd(II)/COF hybrids within an hour under ambient conditions using water as the solvent. Notably, gram‐scale synthesis of Pd(II)/COFs is achievable. The resulting Pd(II)/COFs exhibit superb crystallinity and high surface area, leading to remarkable activity, excellent functionality tolerance, and high recyclability for the Suzuki–Miyaura cross‐coupling reaction of aryl bromides and arylboronic acids at room temperature. This one‐step sonochemical strategy effectively addresses the long‐lasting limitations of traditional multistep synthesis, paving a fast and sustainable avenue to diversified metal/COF hybrids for heterogeneous catalysis and potentially other applications.
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Mechanochemical in Situ Encapsulation of Palladium in Covalent Organic Frameworks
Palladium-encapsulated covalent organic frameworks (Pd/COFs) have garnered enormous attention in heterogeneous catalysis. However, the dominant ex situ encapsulation synthesis is tedious (multistep), time-consuming (typically 4 days or more), and involves the use of noxious solvents. Here we develop a mechanochemical in situ encapsulation strategy that enables the one-step, timeefficient, and environmentally benign synthesis of Pd/COFs. By ball milling COF precursors along with palladium acetate (Pd(OAc)2) in one pot under air at room temperature, Pd/COF hybrids were readily synthesized within an hour, exhibiting high crystallinity, uniform Pd dispersion, and superb scalability up to gram scale. Moreover, this versatile strategy can be extended to the synthesis of three Pd/COFs. Remarkably, the resulting Pd/DMTP-TPB showcases extraordinary activity (96−99% yield in 1 h at room temperature) and broad substrate scope (>10 functionalized biaryls) for the Suzuki−Miyaura coupling reaction of aryl bromides and arylboronic acids. Furthermore, the heterogeneity of Pd/DMTP-TPB is verified by recycling and leaching tests. The mechanochemical in situ encapsulation strategy disclosed herein paves a facile, rapid, scalable, and environmentally benign avenue to access metal/COF catalysts for efficient heterogeneous catalysis.
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- Award ID(s):
- 2100360
- PAR ID:
- 10590328
- Publisher / Repository:
- ACS
- Date Published:
- Journal Name:
- ACS Sustainable Chemistry & Engineering
- Volume:
- 12
- Issue:
- 36
- ISSN:
- 2168-0485
- Page Range / eLocation ID:
- 13535 to 13543
- Subject(s) / Keyword(s):
- mechanochemistry, in situ metal encapsulation, covalent organic frameworks, palladium, heterogeneous catalysis
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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