3D‐Printable Fluoropolymer Gas Diffusion Layers for CO ₂ Electroreduction

Electrocatalytic transformation of carbon dioxide (CO 2 ) and water into chemical feedstocks offers the potential to reduce carbon emissions by shifting the chemical industry away from fossil fuel dependence. We provide a technoeconomic and carbon emission analysis of possible products, offering targets that would need to be met for economically compelling industrial implementation to be achieved. We also provide a comparison of the projected costs and CO 2 emissions across electrocatalytic, biocatalytic, and fossil fuel–derived production of chemical feedstocks. We find that for electrosynthesis to become competitive with fossil fuel–derived feedstocks, electrical-to-chemical conversion efficiencies need to reach at least 60%, and renewable electricity prices need to fall below 4 cents per kilowatt-hour. We discuss the possibility of combining electro- and biocatalytic processes, using sequential upgrading of CO 2 as a representative case. We describe the technical challenges and economic barriers to marketable electrosynthesized chemicals.

Electrolysis offers an attractive route to upgrade greenhouse gases such as carbon dioxide (CO 2 ) to valuable fuels and feedstocks; however, productivity is often limited by gas diffusion through a liquid electrolyte to the surface of the catalyst. Here, we present a catalyst:ionomer bulk heterojunction (CIBH) architecture that decouples gas, ion, and electron transport. The CIBH comprises a metal and a superfine ionomer layer with hydrophobic and hydrophilic functionalities that extend gas and ion transport from tens of nanometers to the micrometer scale. By applying this design strategy, we achieved CO 2 electroreduction on copper in 7 M potassium hydroxide electrolyte (pH ≈ 15) with an ethylene partial current density of 1.3 amperes per square centimeter at 45% cathodic energy efficiency.