(308b) Tutorial on Efficient Electrocatalytic Conversion of CO2 to Intermediates Such As CO and Ethylene

Electroreduction of CO₂ can produce intermediates for fuels or chemicals thus reducing our dependency on dwindling global fossil fuel reserves, while at the same time mitigating anthropogenic CO₂ emissions that have been associated with undesirable climate change effects. Furthermore, driving CO₂ conversion with intermittent renewable energy sources such as wind and solar, has the potential to provide a method for storage of otherwise wasted renewable energy that is produced in excess of grid demand. With the rapid increase in large scale solar and wind energy production farms, the latter is starting to become a frequent occurrence. Over the last decade many researchers have started to pursue electrocatalytic conversion of CO₂ to value-added intermediates such as carbon monoxide (CO), formic acid, ethylene oxide, and ethanol. This tutorial will start by summarizing the state-of-the-art selective, active, and energy efficient catalysts that have been developed for the production of the different aforementioned products. The methods used to characterize these catalysts using in a H-cell or an electrolysis cell under different conditions will be covered, including the importance of electrolyte composition and pH. Special attention will be placed on the preparation of robust electrodes, often gas diffusion electrodes, and their application in electrolysis cells. The tutorial will also cover techno-economic analysis of CO₂ electrolysis for the production of different intermediates, which provides insights into the cost-driving factors and its potential of achieving economic viability for large scale storage of energy from renewable sources or in the reduction of greenhouse gas emissions.