518675 Anion Exchange Membranes for Artificial Photosynthesis: Investigating Structure-Property Relationships in Poly(vinylimidazolium) Materials

Tuesday, June 12, 2018: 3:00 PM
Magnolia (Hilton Lexington)
Blaine Carter, Lawrence Berkeley National Laboratory, Berkeley, CA, Laura Keller, RWTH Aachen University, Aachen, Germany, Matthias Wessling, AVT.CVT, RWTH Aachen University, Aachen, Germany and Daniel J. Miller, Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, CA

Artificial photosynthesis could be a source of carbon neutral fuels and chemicals, converting fluctuating solar energy into chemical energy available on demand. Anion exchange membranes are commonly used in photoelectrochemical CO2 reduction devices, which convert CO2 into alcohol fuels. Optimization of membrane properties is critical to improve device functionality and efficiency. For example, understanding and minimizing the crossover of CO2 reduction products is imperative, since products that permeate across the membrane frustrate product recovery and can be re-oxidized at the anode, which directly compromises device efficiency. Here, we investigate structure-property relationships in poly(vinylimidazolium) anion exchange materials with variable cross-link density and ion exchange capacity. A systematic series of membranes were prepared by UV-photopolymerization of difunctional and monofunctional monomers at various concentrations in water or methanol solutions. The water content, ionic conductivity, and permeability to methanol (a model CO2 reduction product) were evaluated. These initial studies on poly(vinylimidazolium) membranes offer insight into polymer design considerations for anion exchange membranes used in artificial photosynthesis and other electrochemical applications, such as methanol fuel cells.

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