ECO-CBET: Bioelectrochemical manufacturing of high-value chemicals using CO2 as feedstock

Recycling carbon dioxide would help reduce the impact of climate change. It might also help establish a circular economy. This project will evaluate a process to capture CO2 and transform it into a feedstock for microbes. This will be accomplished using a membrane with two functions. The membrane will absorb CO2 from the environment. It will also contain a catalyst to transform the CO2 to acetic acid. The microbes will be modified to produce a range of high value bioproducts using acetic acid as a starting material. Graduate and undergraduate students will participate in research and scientific workshops. Outreach to middle and high schools will encourage women and underrepresented students to participate in STEM-related careers. The goal is to create a process that produces microbial feedstock from recycled CO2. The emphasis is directed towards closing the carbon cycle for acetic acid-based microbial synthesis of high-value products (HVPs) or precursors. Integrated bioelectrochemical cells will be developed and evaluated. The results will be subject to systems level and technoeconomic analyses. The strategy is to use a composite of polymer and metal-organic framework (MOF) as a gas-diffusion layer to increase the CO2 uptake from dilute streams. CO2 will be delivered to a cathode in a single-atom catalyst (SAC) based electrocatalysis configuration to produce acetate. Integrated acetate separation from electrolyte and enrichment of minimal media is then followed by engineered Escherichia coli strains for sustainable synthesis of biomaterials. The economic viability and environmental impact of the integrated bioelectrochemical manufacturing will be assessed. The structural and chemical properties of gas-diffusion electrodes decorated with polymer-MOF and SAC electrocatalysts will be identified. Acetate bioconversion efficiency will be maximized, and cross-contamination between the electrolyzer and bioreactors will be minimized. 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.