Postgraduate Seminar Presentation : Continuous millifluidic reactors for robust production of supported catalyst nanoparticles

Speaker Wong Wai Kwan (Supervisor: A/Prof Saif A Khan)

Host Department of Chemical and Biomolecular Engineering

Date/Time 21 Sep - 21 Sep, 10.00am

Venue E5-02-32 , Faculty of Engineering, National University of Singapore

Synopsis

Noble ultra-small metal nanoparticles, such as palladium, platinum and rhodium, are invaluable catalysts for the synthesis of a plethora of materials, ranging from pharmaceutical drugs to polymers and fertilizers due to their unique catalytic activities and large surface area-to-volume ratios. Conventionally, they are deposited on support material as these ultra-small nanoparticles tend to agglomerate. To achieve excellent catalytic activity, stability and high selectivity towards the desired products, these metal nanoparticles have to be synthesized in a controlled process and be well-dispersed on the support. Specifically, colloidal deposition is the process of choice for synthesis of supported nanoparticles because it enables the deposition of nanoparticles with complex compositions and shapes on the support material, since the physical properties of the colloid nanoparticles are not affected by the deposition process. Typically, colloidal deposition is performed using bulk batch processes, where the size monodispersity and distribution of nanoparticles on supports are difficult to control due to severe mixing limitations. Such drawbacks can be mitigated by the use of continuous flow microfluidic reactors due to their rapid mixing and precise controlled reaction parameters in a small reaction volume. Here, we present a robust triphasic millireactor for continuous synthesis of supported nanoparticles in a single microfluidic reactor by conducting synthesis of ultra-small nanoparticles and their deposition on support material simultaneously. With this continuous flow reactor, we demonstrate the tunability of the coverage of metallic nanoparticles on the support, and also the generality of our method for different nanoparticles types, such as bi-/tri-metallics, and different supports. We envision that this continuous flow reactor can be employed for high throughput production of supported nanoparticles by coupling scaling-up and parallelization, which can likely meet or exceed demand for their application in specialty and fine chemical industries.

Biography