Biopolymer supports for catalytic metal nanoparticles

Metal nanoparticle catalysts have offered routes to greener chemical processes through opportunities to improve catalyst activity, selectivity and the necessary reaction conditions. Paramount to their successful use is both the provision of stability to these high surface energy particles, essential in the prevention of agglomeration, and the recovery of these often precious metals at end of life.

In this project, structured biopolymer materials were produced from cellulose processed using ionic liquid based systems. Catalytic metal nanoparticles (NPs), such as silver NPs, were produced in situ and immobilised in/on these cellulose materials. This led to materials that were suitable for catalytic applications; demonstrated using the Ag-cellulose catalysts (NPs 4 – 8 nm) in the reduction of 4-nitrophenol to 4-aminophenol as a model reaction. The results obtained demonstrate the activity, stability and recyclability of these catalyst materials.

This work will be applicable for use in a continuous flow system; with a novel system in which the Ag-cellulose catalyst is supported on a single rod to simulate a channel of a future monolithic system. Conventionally porous ceramic materials are used for this purpose; however, here the Ag-cellulose catalyst will be integrated with the cellulose content of a wood monolith structure. Thus, presenting a catalyst system produced from renewable materials, with the potential for metal nanoparticle recovery at end of life.