Approaches to Unifying Photoredox Catalysis and Artificial Photosynthesis by Upcycling Non-Biodegradable Plastics
Artificial photosynthesis potentially offers solutions to the world’s looming energy and environmental crises. In this presentation, I will discuss the ongoing challenges of commercializing traditional artificial photosynthetic systems based on water splitting, and highlight the advantages of replacing the water oxidation half-reaction with value-added alternatives, such as plastics upcycling by photocatalytic C-C bond cleavage with tandem functionalization. I will describe my team’s efforts at attempting to bridge artificial photosynthesis with photoredox catalysis through light absorption, charge separation, and both molecular and heterogeneous catalysis. In particular, I plan to focus on our efforts at applying molecular vanadium complexes for selective, ambient condition, photoredox C-C cleavage reactions. We conducted detailed kinetic measurements to identify the fastest catalyst and the critical functional groups required in the substrates. The vanadium photocatalysts were then utilized for the C-C bond cleavage and oxygenation of over 30 substrates, including unactivated, commercially sourced alcohols and even non-biodegradable plastics. Our ongoing efforts to expand the substrate scope and integrate the photocatalytic C-C bond activation into artificial photosynthetic systems will be presented.
Han Sen Soo is an Associate Professor at Nanyang Technological University (NTU) Singapore. He graduated from MIT with Bachelor and Master degrees and completed his Ph.D. work at U. C. Berkeley. Subsequently, he joined the Lawrence Berkeley National Laboratory as a postdoctoral fellow, working on materials and nanotechnology. Han Sen started his career in the Division of Chemistry and Biological Chemistry at NTU in 2012. The overarching theme of his research program is to find ways to use solar and other forms of renewable energy to create fuels and chemical feedstocks from “waste” materials. One of the latest breakthroughs from his group is the demonstration of a way to use light to convert non-biodegradable plastics into formic acid, which can be used in fuel cells.