GOALI: Manufacturing USA: Elastomeric Microparticle-Packed Bed Reactor for Continuous Metal-Mediated Pseudo-Homogeneous Catalysis

A team of researchers from North Carolina State University and Eastman Chemical Company will design and fabricate catalytic microparticles for applications in energy-efficient synthesis of fine chemicals, natural products, and pharmaceuticals using environmentally friendly solvents. The microparticles will act as polymer microreactors with an embedded metal catalyst center. A highly flexible elastomeric microparticle-packed bed reactor will be designed that can simultaneously exhibit the benefits of both homogeneous and heterogeneous catalysis. The research efforts will focus on uncovering design principles that will facilitate the development of highly efficient modular microreaction vessels with high synthetic flexibility.

The efficiency of metal-mediated chemical transformations depends critically on the chemical structure of the reacting species and the reaction environment. The proposed catalytic system is based on crosslinking poly(hydromethyl siloxane)s with functionalized dienes and embedding palladium (Pd) catalysts in such spherical elastomeric scaffolds. A novel catalytic reactor system will be developed that is modular and highly tunable. These attributes are achieved by varying the chemistry of the crosslinker, degree of crosslinking, type, loading, and accessibility of the Pd catalyst, and chemical microenvironment surrounding the Pd catalyst. The elastomeric microparticles will be loaded with Pd nanocatalysts and provide a controlled reaction environment. The Pd catalyst will be ligand-free and thus very reactive; it resides firmly inside a very flexible elastomeric microparticle, which makes the Pd catalyst center mobile locally while simultaneously protecting the microreaction vessel from the outside environment. Chemical adjustability in conjunction with mechanical and structural flexibility, deformability, and swellability in various solvents are key attributes that can make the proposed catalytic system efficient, robust, and scalable for the continuous organic synthesis of fine chemicals and pharmaceuticals. In addition to the scientific and technological impact of the proposed research, the project will be used to train one graduate and two undergraduate students. The research team plans to pursue outreach activities through the Science House program at North Carolina State University aimed at attracting local K-12 students to pursue careers in STEM fields. There is also a plan to recruit women and members of underrepresented groups in STEM fields to participate in the proposed research and outreach programs.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.