Cuixian Yang

Viral-templated palladium nanocatalysts for Suzuki coupling reaction

We demonstrate and thoroughly examine tobacco mosaic virus (TMV)-templated palladium (Pd) nanocatalysts for the ligand-free Suzuki coupling reaction under mild conditions. The surface-assembled TMV templates allow for facile catalyst synthesis under mild aqueous conditions that leads to high Pd surface loading and stability. Further, the chip-based format enables simple catalyst separation and reuse as well as facile product recovery. Reaction condition studies demonstrated that the solvent ratio played an important role in the selectivity of the Suzuki reaction, and that a higher water/acetonitrile ratio significantly facilitated the cross-coupling pathway. We envision that our viral template-based bottom-up assembly approach can be readily extended to other biotemplates, metal catalysts and organic reaction systems.

A Facile Synthesis–Fabrication Strategy for Integration of Catalytically Active Viral-Palladium Nanostructures into Polymeric Hydrogel Microparticles via Replica Molding

The synthesis of small, uniform, well-dispersed and active Pd nanocatalysts under mild conditions in a predictable and controlled manner is an unmet challenge. Viral nanomaterials are attractive biotemplates for the controlled synthesis of nanoparticles due to their well-defined and monodisperse structure along with abundant surface functionalities. Here, we demonstrate spontaneous formation of small (1-2 nm), uniform and highly crystalline palladium (Pd) nanoparticles along genetically modified tobacco mosaic virus (TMV1cys) biotemplates without external reducing agents. The ratio between TMV and Pd precursor plays an important role in the exclusive formation of well-dispersed Pd nanoparticles along TMV biotemplates. The as-prepared Pd-TMV complexes are then integrated into the poly(ethylene glycol) (PEG)-based microparticles via replica molding (RM) technique in a simple, robust and highly reproducible manner. High catalytic activity, recyclability and stability of the hybrid Pd-TMV-PEG microparticles are further demonstrated through dichromate reduction as a model reaction. Taken together, these findings demonstrate a significant step toward simple, robust, and scalable synthesis and fabrication of efficient biotemplate-supported Pd nanocatalysts in readily deployable polymeric scaffolds with high capacity in a controlled manner.

Viral Templated Palladium Nanocatalysts

Palladium (Pd) nanocatalysis plays key roles in many areas from environmental remediation, energy utilization to chemical synthesis. Viruses offer exciting opportunities and advantages as promising nanoparticle synthesis templates due to their controlled dimensions and structures, and the ability to confer precisely spaced functionalities by genetic modification to permit improved and/or tunable metal nanoparticle formation. We have utilized tubular tobacco mosaic virus (TMV) as biologically derived nanotemplates for controlled synthesis of catalytically active Pd nanoparticles. Here we describe key findings and insights gained from our studies on the synthesis and characterization, as well as on both aqueous and organic phase catalytic reactions, dichromate reduction and the Suzuki‐coupling reaction. We hope that the methodologies and results summarized here can spur further interdisciplinary collaboration, and expect that more discoveries and improved performances can be realized with future endeavors.

Integrated Methods to Manufacture Hydrogel Microparticles Containing Viral–Metal Nanocomplexes with High Catalytic Activity

Controlled synthesis of small and catalytically active noble metal nanoparticles under mild aqueous conditions is an unmet challenge. Genetically modified tobacco mosaic virus (TMV) can serve as a preferential precursor adsorption and growth sites for the controlled synthesis of palladium (Pd) nanoparticles with high catalytic activity. Here we describe detailed methods for the synthesis of Pd-TMV nanocomplexes as well as their integration into polymeric hydrogel microparticle platforms with controlled dimensions via a simple replica molding process. Such Pd-TMV-containing hydrogel particles may be useful in environmental remediation of toxic chemicals such as carcinogenic dichromate ions.