Metal catalysts supported by singlechain nanoparticles (SCNP) are highly attractive due to their excellent dispersibility in solution and the unique nanoconfinement effect derived from intramolecular folding. However, a longstanding contradiction exists: good dispersibility usually impairs recyclability, and conventional recovery by highspeed centrifugation is inefficient, solventintensive, and often incomplete.
Now, a team led by Professor Hongting Pu from Tongji University, Shanghai, China, has designed a "beehiveinspired" nanocarrier that elegantly solves this dilemma. The system, reported in Nano Research , uses a dynamic DielsAlder (DA) covalent bond to anchor copper(II)-loaded SCNP onto a maleimidefunctionalized glass surface (SiOx-MI). At elevated temperature (120 °C), the reverse DA reaction releases the SCNP catalysts into the reaction medium, where they efficiently catalyze the oxidative coupling of phenylacetylene. After the reaction, cooling to room temperature triggers regrafting of the SCNP onto the carrier, allowing simple recovery without centrifugation.
"This catalytic system works like a beehive," explains Prof. Pu. "The SCNP catalysts, the 'worker bees', freely leave the hive to perform catalysis, and reliably return to the hive for recovery. The process is highly efficient, ecofriendly, and dramatically reduces solvent waste."
The researchers synthesized four SCNP with hydrodynamic diameters ranging from 8 to 26 nm, all containing 4.5 wt% copper. The smallest SCNP exhibited the fastest catalytic rates due to higher surface area and better accessibility of the active sites. Crucially, the reversible DA grafting enabled the SCNP to be reused for 20 consecutive releasecatalysisrecovery cycles, retaining over 90% conversion and nearperfect selectivity for phenylacetylene over other alkynes.
Smallangle Xray scattering (SAXS) and transmission electron microscopy (TEM) confirmed that the internal cavity structure of the SCNP remained essentially unchanged after 20 cycles. SAXS, Kratky plots and TEM images before and after 20 cycles demonstrate the preservation of the compact spherical morphology. Moreover, the nanocarrier recovery method avoided the mechanical stress and poorsolvent rinsing required by centrifugation, which is known to damage SCNP structure, a point previously highlighted by the Pu group in their studies on reversible polymer networks (ACS Macro Lett. 2023, 12, 1311) and tadpoleshaped SCNP combs (Chem. Sci. 2024, 15, 17590).
In competitive coupling reactions (e.g., mixtures of phenylacetylene with other terminal alkynes), the SCNP catalysts showed exclusive selectivity for phenylacetylene, in sharp contrast to free Cu(OAc)2, which produced mixtures. The authors attribute this high selectivity to the constrained cavity environment around the copper active sites, reminiscent of enzymelike catalysis. This is consistent with their earlier findings on singlechain polymer nanoparticles carrying cuprous catalysts (Eur. Polym. J. 2021, 143, 110194).
"Our hiveinspired nanocarrier not only solves the recyclability issue but also preserves the exceptional selectivity and activity of SCNP catalysts," says Prof. Pu. "In the future, this concept can be extended to other catalysts and solid carriers, such as films, sheets, or microporous materials, paving the way for truly sustainable nano-catalysis."
This work was supported by National Natural Science Foundation of China (52573344), Fundamental Research Funds for the Central Universities (China) (0500219216), and Shanghai Synchrotron Radiation Facility (SSRF, China).
DOI Link:
https://doi.org/10.26599/NR.2026.94908716
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
