Joel Graves
Pronouns: He/Him/His
UROP Fellowship: University of Michigan Energy Institute
Research Mentor(s): Nicholas Kotov, PhD
Department of Chemical Engineering
Presentation Date: Wednesday, July 29, 2020 | Session 2 | Presenter: 6
Authors: Joel Graves, Elizabeth Wilson, Nicholas Kotov
Abstract
Electrochemical CO2 reduction offers a unique and green production scheme for useful C1 and C2 hydrocarbon fuels and species such as methane, methanol, and ethylene.[1][2][3] However, traditional aqueous CO2 electroreduction requires high overpotentials and offers limited Faradaic efficiency due to low solubility of CO2 in water and competition with the hydrogen evolution reaction (HER).[1][3] Supercritical phase CO2 (scCO2) offers an advantage over an aqueous system by greatly increasing the relative concentration of CO2 available for reduction at the electrode. However, scCO2 exhibits poor ionic conductivity, so the introduction of an electrolyte is necessary to facilitate ion transfer.[5] A multifaceted solution to these issues is the use of supercritical phase CO2 in a biphasic emulsion system stabilized by novel Hedgehog particles (HPs)[6]. HPs are spiked microparticles that exhibit unique omni-dispersibility in media of all polarities without any additional surfactant. HPs allow a simple, economically feasible aqueous electrolyte to be used in a biphasic system by promoting a stable Pickering emulsion. HPs are highly recyclable, stable, and finely tunable for use in many applications. Potential functionalization includes catalytic and conductive metal surface deposition, particle and nanorod size selectivity, and induced magnetism. In this system, HPs encourage ion and electron flow from the aqueous electrolyte to the CO2 phase by increasing the interfacial surface area between the two phases in the system. This has been shown to increase methane yield 3.5x compared to experiments without HPs present. The goal of this project is to investigate how the functionalization of HPs can aid in tuning product selectivity and further increasing product yield. Specifically, I am using Density Functional Theory (DFT) to investigate predicted reaction mechanisms and product selectivity for various HP surface functionalizations. Copper, in particular, is of interest due to its unique ability to form myriad hydrocarbon products because it can directly protonate CO* intermediates.[7] Its low affinity for the HER reaction is also of interest, as it is the only metal with a negative adsorption energy for CO* and a positive one for H*.[3] Initial calculations suggest functionalized HPs have the potential to augment product selectivity and yield with experimental trails to substantiate this claim currently in progress.
References:
[1] L. Fan, C. Xia, F. Yang, J. Wang, H. Wang, Y. Lu, Strategies in catalysts and
electrolyzer design for electrochemical CO2 reduction toward C2+ products. Sci. Adv.
6, eaay3111 (2020).
[2] Peterson, Andrew A. et al. “How copper catalyzes the electroreduction of carbon
dioxide into hydrocarbon fuels.” (2010).
[3] Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous
Electrolyte Stephanie Nitopi, Erlend Bertheussen, Soren B. Scott, Xinyan Liu, Albert
K. Engstfeld, Sebastian Horch, Brian Seger, Ifan E. L. Stephens, Karen Chan, Christopher Hahn, Jens K. Nørskov, Thomas F. Jaramillo, and Ib Chorkendorff
Chemical Reviews 2019 119 (12), 7610-7672
DOI: 10.1021/acs.chemrev.8b00705
[4] Yin-Jia Zhang, Vijay Sethuraman, Ronald Michalsky, and Andrew A. Peterson
ACS Catalysis 2014 4 (10), 3742-3748
DOI: 10.1021/cs5012298 https://doi.org/10.1021/cs5012298
[5] O. Melchaeva, P. Voyame, V. C. Bassetto, M. Prokein, M. Renner, E. Weidner, M.
Petermann, A. Battistel, ChemSusChem 2017 , 10 , 3660. https://doi.org/10.1002/cssc.201701205
[6] Bahng, J., Yeom, B., Wang, Y. et al. Anomalous dispersions of ‘hedgehog’ particles.
Nature 517, 596–599 (2015). https://doi.org/10.1038/nature14092
[7] J. W. Vickers, D. Alfonso, D. R. Kauffman, Energy Technol. 2017 , 5 , 775.
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Research Disciplines
Engineering
