Maximizing Ag Utilization in High-Rate CO2 Electrochemical Reduction with a Coordination Polymer-Mediated Gas Diffusion Electrode

• Published in: ACS energy letters Vol. 4; no. 8; pp. 2024 - 2031
• Main Authors: Wang, Riming, Haspel, Henrik, Pustovarenko, Alexey, Dikhtiarenko, Alla, Russkikh, Artem, Shterk, Genrikh, Osadchii, Dmitrii, Ould-Chikh, Samy, Ma, Ming, Smith, Wilson A, Takanabe, Kazuhiro, Kapteijn, Freek, Gascon, Jorge
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.08.2019
• ISSN: 2380-8195; 2380-8195
• DOI: 10.1021/acsenergylett.9b01509

We report the preparation and electrocatalytic performance of silver-containing gas diffusion electrodes (GDEs) derived from a silver coordination polymer (Ag-CP). Layer-by-layer growth of the Ag-CP onto porous supports was applied to control Ag loading. Subsequent electro-decomposition of the Ag-CP resulted in highly selective and efficient CO2-to-CO GDEs in aqueous CO2 electroreduction. Afterward, the metal–organic framework (MOF)-mediated approach was transferred to a gas-fed flow electrolyzer for high current density tests. The in situ formed GDE, with a low silver loading of 0.2 mg cm–2, showed a peak performance of j CO ≈ 385 mA cm–2 at around −1.0 V vs RHE and stable operation with high FECO (>96%) at j Total = 300 mA cm–2 over a 4 h run. These results demonstrate that the MOF-mediated approach offers a facile route for manufacturing uniformly dispersed Ag catalysts for CO2 electrochemical reduction by eliminating ill-defined deposition steps (drop-casting, etc.) while allowing control of the catalyst structure through self-assembly.