Lawrence Berkeley National Laboratory
Sequential Cascade Electrocatalytic Conversion of Carbon Dioxide to C-C Coupled Products
- Author(s): Gurudayal, G
- Perone, D
- Malani, S
- Lum, Y
- Haussener, S
- Ager, JW
- et al.
Published Web Locationhttps://doi.org/10.1021/acsaem.9b00791
© Copyright 2019 American Chemical Society. Cascade catalytic processes perform multistep chemical transformations without isolating the intermediates. Here, we demonstrate a sequential cascade pathway to convert CO2 to C2+ hydrocarbons and oxygenates in a two-step electrocatalytic process using CO as the intermediate. CO2 to CO conversion is performed by using Ag, and further conversion of CO to C-C coupled products is performed with Cu. Temporal separation between the two reaction steps is accomplished by situating the Ag electrode upstream of the Cu electrode in a continuous flow reactor. Convection-diffusion simulations and experimental evaluation of the electrodes individually are performed to identify optimal conditions. With the upstream Ag electrode poised at -1 V versus reversible hydrogen electrode in a flow of CO2-saturated water in aqueous carbonate buffer, over 80% of the CO can be converted on the downstream Cu electrode. When the Ag electrode is on, a supersaturation of CO is achieved near the Cu electrode, which leads to a relative increase in the formation rate of C2 and C3 oxygenates as compared to ethylene.