Mesh GDEs: An alternative to carbon-based electrodes for CO2 reduction at higher current densities

Abstract

Scaling up the electrolysis of CO2 to multi-carbon products remains a challenge due to the instability of conventional carbon-based gas diffusion materials at higher current densities. In this study, we investigate the use of a CuMesh-Polytetrafluoroethylene (PTFE) sandwich electrode, which is both scalable and can conduct large amounts of current on account of its metallic structure. Although we showcase CO2RR activity up to –500 mA cm−2, the trends we observe indicate this value can be pushed beyond –1 A cm−2. We find that we can achieve a higher ethylene (C2H4) partial current density by increasing mesh sizes (i.e., smaller pores). Furthermore, 100 h durability tests revealed that both morphological changes and reaction-driven electrolyte contamination are critical for steady C2H4 performance even if flooding is mitigated. Thus, substantial room for optimization exists for future works. To conclude, the mesh based GDE we propose herein opens up possibilities for achieving robust industrial-scale CO2 and CO reduction.