3D-Printable Fluoropolymer Gas Diffusion Layers for CO2 Electroreduction

The electrosynthesis of value-added multicarbon products from CO2 is a promising strategy to shift chemical production away from fossil fuels. Particularly important is the rational design of gas diffusion electrode (GDE) assemblies to react selectively, at scale, and at high rates. However, the understanding of the gas diffusion layer (GDL) in these assemblies is limited for the CO2 reduction reaction (CO2RR): particularly important, but incompletely understood, is how the GDL modulates product distributions of catalysts operating in high current density regimes > 300 mA cm(-2). Here, 3D-printable fluoropolymer GDLs with tunable microporosity and structure are reported and probe the effects of permeance, microstructural porosity, macrostructure, and surface morphology. Under a given choice of applied electrochemical potential and electrolyte, a 100x increase in the C2H4:CO ratio due to GDL surface morphology design over a homogeneously porous equivalent and a 1.8x increase in the C2H4 partial current density due to a pyramidal macrostructure are observed. These findings offer routes to improve CO2RR GDEs as a platform for 3D catalyst design.

Automated summary

The rational design of gas diffusion electrode assemblies is crucial for selective and high-rate CO2 conversion to value-added multicarbon products. The study found that the microporosity and structure of gas diffusion layers can significantly affect the product distributions of catalysts operating at high current densities, with surface morphology design leading to a 100x increase in the C2H4:CO ratio and a pyramidal macrostructure causing a 1.8x increase in the C2H4 partial current density. These findings suggest new routes for improving CO2 reduction GDEs as a platform for 3D catalyst design.