2017 Annual Meeting

(66d) A Carbon Nanotube Supported Gold Catalyst for the Electroreduction of Carbon Dioxide (CO2)

Authors

Sumit Verma - Presenter, University of Illinois at Urbana-Champaign
Yuki Hamasaki, Kyushu University
Chaerin Kim, Kyushu University
Wenxin Huang, Kyushu University
Shawn Lu, University of Illinois at Urbana-Champaign
Molly Jhong, University of Illinois at Urbana-Champaign
Tsuyohiko Fujigaya, Kyushu University
Naotoshi Nakashima, Kyushu University
Paul J. A. Kenis, University of Illinois at Urbana-Champaign
The electrochemical reduction of carbon dioxide (CO2) to value added chemicals (such as formic acid, carbon monoxide (CO), ethylene, and ethanol) has been proposed as a potential strategy for the utilization of excess anthropogenic CO2 emissions.[1, 2] In particular, the electroreduction of CO2 to CO seems interesting, as CO (either alone or in combination with H2i.e., syngas) can be used as a platform chemical to produce a variety of hydrocarbons. However, even after a few decades of research, electrochemical systems that can produce CO via the electroreduction of CO2 at industrially relevant rates (partial current density for CO >150 mA cm-2) and low overall cell overpotentials (absolute value <1V),[3] remain difficult to develop.

In this presentation, we will report a supported gold (Au) catalyst that exhibits remarkably high activity (partial current density for CO ~158 mA cm-2) at low cell overpotentials (~-0.94 V), for the electroreduction of CO2 to CO. The catalyst was synthesized via an in situ chemical reduction of the Au precursor (chloroauric acid) on a polybenzimidazole wrapped carbon nanotube support. The electrochemical characterization was performed in a flow electrolyzer to avoid mass transfer limitations associated with the low solubility of CO2 in aqueous solutions.[4] Furthermore, we will also discuss the effect of electrolyte composition (concentration and pH) with respect to increasing the activity and lowering the overpotential required for the electroreduction of CO2 to CO on the supported Au catalyst. The mechanistic implications of such a behavior will also be discussed.

References:

[1] A.M. Appel, J.E. Bercaw, A.B. Bocarsly, H. Dobbek, D.L. DuBois, M. Dupuis, J.G. Ferry, E. Fujita, R. Hille, P.J.A. Kenis, C.A. Kerfeld, R.H. Morris, C.H.F. Peden, A.R. Portis, S.W. Ragsdale, T.B. Rauchfuss, J.N.H. Reek, L.C. Seefeldt, R.K. Thauer, G.L. Waldrop, Chem. Rev. 2013, 113, 6621-6658.

[2] H.R.M. Jhong, S. Ma, P.J.A. Kenis, Curr. Opin. Chem. Eng. 2013, 2, 191-199.

[3] S. Verma, B. Kim, H.R.M. Jhong, S. Ma, P.J.A. Kenis, ChemSusChem 2016, 9, 1972-1979.

[4] D.T. Whipple, E.C. Finke, P.J.A. Kenis, Electrochem. Solid-State Lett. 2010, 13, B109-B111.