The CO2 electroreduction reaction (CO2RR) is a promising method to produce fuels and useful chemicals in a clean and sustainable way. Electricity can be derived from renewable energy sources, such as solar or wind, and can be converted into chemical energy stored in the form of chemical bonds. A variety of products (carbon monoxide, methanol, methane, ethanol, ethylene, n-propanol) can be produced by CO2RR. However, products with heteroatoms (ex. C and N) like acetamide or urea are carry even more commercial value. There is a recent push in co-reacting N-sources such as N2 or ammonia with CO2 to generate products with C-N bonds. However, there remains much to be done in terms of developing efficient reaction routes and unveiling the precise surface reaction mechanism. To this end, we present a novel electrochemical system which co-reacts ammonia and CO2 at a gas-liquid-solid triple phase boundary to produce acetamide and formamide over Cu-based catalysts. Electrolysis experiments show that formamide is preferential to be formed on Cu catalysts, while CuO tend to produce acetamide. We combine electrochemical methods with in-situ spectroscopy to reveal the intermediate of the reactions and subsequently propose a likely set of reaction pathways. The faradaic efficiency (FE) of CuO reaches maximum for the formation of acetamide at -1.8V, which is 0.63%. While for Cu, the formation of formamide reaches maximum (0.32% FE) at -2.0V. As the formation of acetamide and acetate share the same intermediate, the production of formamide and formate may also undergo the same reaction pathway at the initial stage of the reaction.

Electrosynthesis of amides by co-reduction of carbon dioxide and ammonia

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.