Electrochemical reduction of carbon dioxide to formate in a flow cell on CuSx grown by atomic layer deposition

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Materials Today Sustainability, Volume 24
Transition metal chalcogenides (TMCs) are promising pre-catalysts for tuning the selectivity of electrochemical carbon dioxide (CO2) reduction (CO2R). Atomic layer deposition (ALD) enables well-controlled growth of thin TMC films on various gas diffusion electrodes. Herein, we have studied the CO2R performance of ALD-grown copper sulfide (CuSx) in a flow cell. The effects of electrode configuration, electrolyte concentration, temperature, and electrolysis time were carefully studied, combined with pre- and post-electrolysis physico-chemical analyses of the films. The unique selectivity of sulfur-doped Cu towards formate was retained with Faradaic efficiencies between 40 and 60%, but slow selectivity changes were observed over time. Major loss of sulfur was encountered during the initial 5-min reduction period, and after that, progressive formation of nanoparticles could be observed. Comparisons to ALD-grown Cu thin film and CuSx-modified Cu foam electrodes verified the importance of sulfur and suggested that other electrocatalyst films could be easily realized with ALD.
Funding Information: M.P. acknowledges funding from the Academy of Finland by the profiling action on Matter and Materials (grant no. 318913). M.S. and T.K. acknowledge funding from Jane and Aatos Erkko foundation (the USVA project). Dr. Timo Hatanpää is thanked for synthesizing the Cu(dmap) 2 precursor. Mr. Chao Zhang is thanked for the ALD copper film depositions. Dr. Lilian Moumaneix is thanked for the TEM images. This work made use of Aalto University RawMatters, Bioeconomy, and OtaNano Low Temperature Laboratory and Nanomicroscopy Center facilities, and the ALD center Finland research infrastructure. Publisher Copyright: © 2023 The Author(s)
ALD, Copper sulfide, Electrochemical CO reduction, Electrolyte concentration effects, Temperature effects
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Suominen, M, Mäntymäki, M, Mattinen, M, Sainio, J, Putkonen, M & Kallio, T 2023, ' Electrochemical reduction of carbon dioxide to formate in a flow cell on CuS x grown by atomic layer deposition ', Materials Today Sustainability, vol. 24, 100575 . https://doi.org/10.1016/j.mtsust.2023.100575