Ruthenium-Substituted Polyoxoanion Serves as Redox Shuttle and Intermediate Stabilizer in Selective Electrooxidation of Ethylene to Ethylene Glycol
The high carbon intensity of present-day ethylene glycol (EG) production motivates interest in electrifying ethylene oxidation. Noting poor kinetics in prior reports of the organic electrooxidation of small hydrocarbons, we explored the design of mediators that activate and simultaneously stabilize light alkenes. A ruthenium-substituted polyoxometalate (Ru-POM, {Si[Ru(H<sub>2</sub>O)W<sub>11</sub>O<sub>39</sub>]}<sup>5-</sup>) achieves 82% faradaic efficiency in EG production at 100 mA/cm<sup>2</sup> under ambient conditions. Via the union of <i>in situ</i> spectroscopic techniques, electrochemical studies, and density functional theory calculations, we find evidence of a two-step oxidation mechanism: Ru-POM first undergoes electrochemical oxidation to the high valent state, activating ethylene via partial oxidation and forming an intermediate complex; this intermediate complex then migrates to the anode where it undergoes further oxidation to produce EG. The Ru-POM-mediated electrocatalytic system reduces the projected energy consumption required in EG production, requiring 9 GJ per ton of EG (and accompanied by 0.04 ton H<sub>2</sub> coproduction), compared to 20-30 GJ/ton in typical prior processes.
Authors
- Ke Xie (ORCID: https://orcid.org/0000-0003-4220-272X)
- Pengfei Ou (ORCID: https://orcid.org/0000-0002-3630-0385)
- William A. Goddard (ORCID: https://orcid.org/0000-0003-0097-5716)
- Xinqi Chen (ORCID: https://orcid.org/0009-0005-5340-0520)
- Weiyan Ni (ORCID: https://orcid.org/0000-0003-0234-4483)
- Vinayak P. Dravid (ORCID: https://orcid.org/0000-0002-6007-3063)
- Gloria H. Su (ORCID: https://orcid.org/0000-0002-5158-6019)
- Edward Hartley Sargent (ORCID: https://orcid.org/0000-0003-0396-6495)
- Jiaqi Yu (ORCID: https://orcid.org/0000-0001-7412-2746)
- Neil M. Schweitzer (ORCID: https://orcid.org/0000-0002-8284-6944)
- Débora Motta Meira (ORCID: https://orcid.org/0000-0002-7529-2736)
- Yi Yang (ORCID: https://orcid.org/0000-0002-7775-6856)
- Q. Chen
- Yuan Liu (ORCID: https://orcid.org/0000-0001-8611-1673)
- Charles B. Musgrave (ORCID: https://orcid.org/0000-0002-3432-0817)
- Cong Tian (ORCID: https://orcid.org/0000-0002-1260-3402)
- Xiaobing Hu (ORCID: https://orcid.org/0000-0002-9233-8118)
- Heejong Shin
Institutions
- Northwestern University (US)
- California Institute of Technology (US)
- Argonne National Laboratory (US)
- Canadian Light Source (Canada) (CA)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2024-11-13
- DOI
- https://doi.org/10.1021/jacs.4c11891
- Citations
- 15
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 1.54
Funders
- International Institute for Nanotechnology, Northwestern University
- Division of Materials Research
- Division of Electrical, Communications and Cyber Systems
- Division of Chemistry
- Basic Energy Sciences
- Argonne National Laboratory