Efficient Electrochemical Reduction of CO2 to Ethylene

Wednesday, 4 October 2017: 15:50
National Harbor 6 (Gaylord National Resort and Convention Center)
P. J. A. Kenis and A. A. Gewirth (University of Illinois at Urbana-Champaign, Int Inst for Carbon-Neutral Energy Research (WPI-I2CNER))
A significant reduction in atmospheric carbon dioxide (CO2) emissions as well as in the development of alternative energy sources will be critical to curb the unwanted effects of climate change (e.g., global warming, erratic weather patterns) and to reduce our dependence on fossil fuels. A number of strategies will need to be pursued simultaneously to indeed reduce anthropogenic CO2 emissions. One such strategy is the use of CO2 as a feedstock for the production of useful chemicals (formic acid, carbon monoxide, hydrocarbons, or alcohols) via electrochemical reduction. This type of electrolysis processes can be driven in a cost effective and sustainable manner if otherwise-wasted renewable energy produced in excess of grid demand is used.

Over the past decade, significant advances have been made in the efficient electrocatalytic conversion of CO2 to carbon monoxide (to be used for dense energy carrier production) with scale up and commercialization activities now ongoing. The production of other interesting chemicals such as methanol and ethylene via electroreduction of CO2 has been lagging.

This presentation will report on our recent progress to in developing ever more active and especially selective catalysts for the production of ethylene and ethanol. Many researchers are pursuing Cu-based catalysts for this task. While reasonable conversion rates can be achieved (overall current densities exceeding 100 mA/cm2), the main challenge has been achieving selectivity for the desired products of ethylene and ethanol. Typically, other gaseous products such as CO, hydrogen and methane are formed in significant amounts, in addition to ethylene and ethanol. Here we will report our work on the development of Cu-based catalysts that produce 70-80% ethylene and ethanol, at a combined rate exceeding 170 mA/cm2. The presentation will also include an analysis of economic feasibility for the production of ethylene from CO2.