Selective and Stable Ethanol Synthesis via Electrochemical CO 2 Reduction in a Solid Electrolyte Reactor

Wi, Tae-Ung [Rice University, Houston, TX (United States)] (ORCID:000000028295825X); Levell, Zachary H. [University of Texas at Austin, TX (United States)]; Hao, Shaoyun [Rice University, Houston, TX (United States)] (ORCID:000000018353518X); Elgazzar, Ahmad [Rice University, Houston, TX (United States)] (ORCID:0000000314534938); Zhu, Peng [Rice University, Houston, TX (United States)] (ORCID:0000000288550335); Feng, Yuge [Rice University, Houston, TX (United States)] (ORCID:0000000300936717); Chen, Feng-Yang [Rice University, Houston, TX (United States)] (ORCID:000000023113383X); Lam, Wei Ping [Rice University, Houston, TX (United States)]; Shakouri, Mohsen [University of Saskatchewan, Saskatoon (Canada)]; Liu, Yuanyue [University of Texas at Austin, TX (United States)] (ORCID:0000000258808649); Wang, Haotian [Rice University, Houston, TX (United States)] (ORCID:0000000235528978)

doi:10.1021/acsenergylett.4c03091

DOE OSTI · 2502105

Selective and Stable Ethanol Synthesis via Electrochemical CO 2 Reduction in a Solid Electrolyte Reactor

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Abstract

Electrochemical CO 2 reduction to ethanol faces challenges such as low selectivity, a product mixture with liquid electrolyte, and poor catalyst/reactor stability. Here, we developed a grain-rich zinc-doped Cu 2 O precatalyst that presented a high ethanol Faradaic efficiency of over 40% under a current density of 350 mA·cm –2 . Our density functional theory (DFT) simulation suggested that Zn atoms inside the structure have a greater carbophilicity than the Cu atoms to help facilitate *CHCHO formation, a key reaction intermediate toward ethanol instead of other C 2 products. Here, a high Faradaic efficiency ratio between ethanol and ethylene (FE EtOH /FE C2H4 ) reached 2.34 in the zinc-doped Cu 2 O precatalyst, representing an over 4-fold improvement compared to bare Cu 2 O precatalyst. By integrating this Cu-based catalyst into a porous solid electrolyte (PSE) reactor with a salt-managing design, we achieved stable ethanol production for over 180 h under a current density of 250 mA·cm –2 while maintaining ethanol selectivity at ~30%.

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Wi, Tae-Ung [Rice University, Houston, TX (United States)] (ORCID:000000028295825X), Levell, Zachary H. [University of Texas at Austin, TX (United States)], Hao, Shaoyun [Rice University, Houston, TX (United States)] (ORCID:000000018353518X), Elgazzar, Ahmad [Rice University, Houston, TX (United States)] (ORCID:0000000314534938), Zhu, Peng [Rice University, Houston, TX (United States)] (ORCID:0000000288550335), Feng, Yuge [Rice University, Houston, TX (United States)] (ORCID:0000000300936717), Chen, Feng-Yang [Rice University, Houston, TX (United States)] (ORCID:000000023113383X), Lam, Wei Ping [Rice University, Houston, TX (United States)], Shakouri, Mohsen [University of Saskatchewan, Saskatoon (Canada)], Liu, Yuanyue [University of Texas at Austin, TX (United States)] (ORCID:0000000258808649), Wang, Haotian [Rice University, Houston, TX (United States)] (ORCID:0000000235528978). 2025-01-15. Selective and Stable Ethanol Synthesis via Electrochemical CO 2 Reduction in a Solid Electrolyte Reactor. https://doi.org/10.1021/acsenergylett.4c03091

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