(180aw) Facile Integration of Catalytically Active Viral-Palladium Nanocluster Complexes Into Polymeric Hydrogel Microparticles Via Replica Molding

We demonstrate spontaneous formation of 1~2 nm palladium (Pd) particles along the tobacco mosaic virus (TMV) biotemplates without the addition of external reducing agents.  The ratio between TMV and Pd precursor plays an important role in the controllable formation of uniform and well-dispersed Pd nanoparticles along TMV templates.  High-resolution TEM revealed extensive high order network formation by end-to-end assembly of the Pd-TMV complexes as well as the highly crystalline nature {111} of the Pd clusters.  The as-prepared Pd-TMV complexes are stable upon arduous separation procedures and can be uniformly suspended in the poly(ethylene glycol)(PEG)-based solutions.  Simple and robust replica molding (RM) technique was then utilized to fabricate hybrid microparticles with Pd-TMV complexes uniformly encapsulated in PEG-DA hydrogel matrices for catalytic applications.  The catalytic activity, stability (including good recyclability and extended shelf life) of the hybrid microparticles are further demonstrated via the dichromate reduction as the model reaction.  Combined these findings demonstrate a significant step toward simple, robust, and scalable procedures for the fabrication of efficient biotemplate-supported Pd nanocatalysts seamlessly integrated in readily applicable polymeric formats with high capacity in a well-controlled manner.