Reactor design and integration with product detection to accelerate screening of electrocatalysts for carbon dioxide reduction
Abstract
Identifying new catalyst materials for complex reactions such as the electrochemical reduction of CO_2 poses substantial instrumentation challenges due to the need to integrate reactor control with electrochemical and analytical instrumentation. Performing accelerated screening to enable exploration of a broad span of catalyst materials poses additional challenges due to the long time scales associated with accumulation of reaction products and the detection of the reaction products with traditional separation-based analytical methods. The catalyst screening techniques that have been reported for combinatorial studies of (photo)electrocatalysts do not meet the needs of CO_2 reduction catalyst research, prompting our development of a new electrochemical cell design and its integration to gas and liquid chromatography instruments. To enable rapid chromatography measurements while maintaining sensitivity to minor products, the electrochemical cell features low electrolyte and head space volumes compared to the catalyst surface area. Additionally, the cell is operated as a batch reactor with electrolyte recirculation to rapidly concentrate reaction products, which serves the present needs for rapidly detecting minor products and has additional implications for enabling product separations in industrial CO_2 electrolysis systems. To maintain near-saturation of CO_2 in aqueous electrolytes, we employ electrolyte nebulization through a CO_2-rich headspace, achieving similar gas-liquid equilibration as vigorous CO_2 bubbling but without gas flow. The instrument is demonstrated with a series of electrochemical experiments on an Au-Pd combinatorial library, revealing non-monotonic variations in product distribution with respect to catalyst composition. The highly integrated analytical electrochemistry system is engineered to enable automation for rapid catalyst screening as well as deployment for a broad range of electrochemical reactions where product distribution is critical to the assessment of catalyst performance.
Additional Information
© 2018 AIP Publishing. (Received 24 July 2018; accepted 2 December 2018; published online 26 December 2018) This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993. We thank Dr. Lan Zhou for providing the Pd-Au composition spread library.Attached Files
Published - 1.5049704.pdf
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Additional details
- Eprint ID
- 91975
- Resolver ID
- CaltechAUTHORS:20190102-092233752
- Department of Energy (DOE)
- DE-SC0004993
- Created
-
2019-01-02Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP