2008
Nickel Phosphides as Catalysts for Direct Electrochemical CO2 Reduction to Important Renewable Polymers

Tuesday, 30 May 2017
Grand Ballroom (Hilton New Orleans Riverside)
K. U. D. Calvinho, A. B. Laursen, T. A. Goetjen, M. Greenblatt, and G. C. Dismukes (Rutgers University)
Copper1 and noble-metal alloys2 have been shown to catalyze the electrochemical reduction of CO2 to hydrocarbons such as methane (C1) and ethylene (C2). C1 and C2 hydrocarbons are the simplest building blocks for the synthesis of most industrial products and are therefore common chemical feedstocks. However, the production of hydrocarbons in aqueous solution is highly energy-consuming mainly due to the over-potential needed to overcome the transition states in C1 and C2 synthesis. In addition, there are significant efficiency losses due to the concomitant H2 production that is kinetically and thermodynamically favored under these conditions. As ethylene and methane from fossil source are comparatively cheap, the high cost of electricity makes the production of these simple hydrocarbons prohibitively expensive.

We have developed a noble metal free catalyst that is able to reduce carbon dioxide to hydrocarbons at lower over-potentials than copper (-0.6 V vs RHE), with significant suppression of the hydrogen production compared to the CO2 free environment. In addition, by changing the reactor configuration, CO2 may now be converted to a valuable polymer with composition akin to an aldehyde-carbonate co-polymer. This solid product can easily be de-polymerized to its parent monomers by changing pH. The resulting complex organic acids and aldehydes produced in at only -0.9 V vs RHE, have a significantly increased value to the simple hydrocarbons making this a very promising technology.

Supported by the BASF Corporation Catalysis Division Fellowship.

References:

(1) Hori, Y.; Kikuchi, K.; Suzuki, S. Chem. Lett. 1985, No. 11, 1695–1698.

(2) Kortlever, R.; Peters, I.; Balemans, C.; Kas, R.; Kwon, Y.; Mul, G.; Koper, M. T. M. Chem. Commun. 2016, 52, 10229–10232.