(182f) Electrochemical Conversion of CO2 to Syngas in An Electrochemical Reactor

Significant reductions in carbon dioxide emissions and the development of non-fossil fuel alternative energy sources is critical to both minimize the effects of CO2 as a green-house gas and reduce our dependence on imported non-renewable energy. In order for renewable and carbon neutral energy sources to replace fossil fuels, technological advances are needed that will allow their penetration into the energy market. The electrochemical reduction of CO2 has to potential to help overcome several of the challenges facing the implementation of carbon neutral energy sources. The electrochemical conversion of CO2 into fuels allows the storage of electrical energy in chemical form, which is important considering that currently over 75% of carbon neutral fuels produce electricity. Storing this electrical energy is high density chemical form would facilitate the penetration of carbon neutral energy into the transportation sector, which makes up a large portion of our energy use but has only 3% supplied by renewable sources. Furthermore, the ability store electricity would aid the expansion of popular renewable sources such as wind and solar that are intermittent and require output leveling. In particular, the production of CO from CO2 is attractive due to its versatility as a feedstock in Fischer-Tropsch synthesis to a variety of products including liquid hydrocarbon fuels. However, before the electrochemical reduction of CO2 can be viable, significant improvements in the energy efficiency and current densities of the process need to be achieved. One of the main obstacles to this is high overpotentials due the formation of the CO2.- intermediate. Significant improvements could be made by finding conditions (such as electrolytes) and catalysts that stabilize this intermediate. We have developed a microfluidic reactor that employs a flowing electrolyte in lieu of a membrane and allows greater flexibility in reactor conditions. In this presentation we will report our studies investigating the effects of electrolyte pH, electrolyte species, and temperature on the energy efficiency and current density of the electrochemical reduction of CO2 to CO.