The direct electroreduction of CO2 to pure CO streams has attracted much attention for both academic research and industrial polymer synthesis development. Here, we explore catalytically very active, coral-structured Ag catalyst for the generation of pure CO from CO2-feeds in lab-bench scale zero-gap CO2 electrolyzer. Coral-shaped Ag electrodes achieved CO partial current densities of up to 312 mA cm−2, EECO of 38%, and FECO clearly above 90%. In-situ/operando X-ray Absorption Spectroscopy revealed the sustained presence of Ag+ subsurface species, whose local electronic field effects constitute likely molecular origins of the favorable experimental kinetics and selectivity. In addition, we show how electrode flooding in zero-gap CO2 electrolyzer compromises efficient CO2 mass transfer. Our studies highlight the need for a concomitant consideration of factors related to intrinsic catalytic activity of the active phase, its porous structure and its hydrophilicity/phobicity to achieve a sustained high product yield in AEM zero-gap electrolyzer.
- AEM zero-Gap electrolyzer
- CO production
- CO reduction reaction (CORR)
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering