CAS: Lignin Valorization via Microscopic Reverse Biosynthesis

New York University, New York NY

Investigators

Abstract

With the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Tianning Diao of New York University is developing methods to convert waste from the pulp and paper industry to useful chemical feedstocks. The chemical products could be used as building blocks for the synthesis of polymers (plastics) and value-added complex molecular targets with useful biological activity (e.g. pesticides, agrochemicals, pharmaceuticals). If successful, the process would improve the overall efficiency of biomass conversion and mitigate waste generated from biorefinery and the paper industry. The idea is to use biomass or lignin as a sustainable source of feedstock chemicals and as an alternative to petroleum-based chemical feedstocks. The project provides opportunities for graduate and undergraduate students to receive training at the interface of organic, inorganic, and green chemistry. Outreach programs area also being developed to empower members of the LGBTQ+ community and encourage them to pursue a career in science, technology, engineering, and mathematics (STEM). An initiative to combine art with chemistry through social media engages the public and promotes interest in chemistry to the greater community. A standing challenge in biomass conversion is the selective degradation of lignin, an abundant natural source for substituted aromatic molecules. This project seeks to address this challenge by developing a method inspired by the biosynthesis route of lignin, which proceeds through a series of oxidation and radical coupling processes to form the irregular lignin polymer. Specificially, a Ti(III)-mediated process is beginning to show promise for lignin depolymerization, and will be studied mechanistically and optimized. Electrocatalytic methods will also be explored. Catalysts that appear to formally reverse the biosynthesis route may be exploitable to achieve high selectivity in lignin depolymerization, an area that is ripe for development given the strong international interest in replacing petroleum feedstocks with biorenewable chemical feedstocks. 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.