Electroreduction of CO2 to Synthesis Gas and Hydrocarbons on Doped Carbons

Strategies to close the anthropogenic carbon cycle through a renewable energy-driven efficient chemical conversion of CO₂ into usable chemical feeds have become a scientific priority. Conversion of CO₂ rich streams from steel mills, concrete- or coal-fired power plants, into syn-gas alcohols or hydrocarbons is of tremendous interest for industry. Of all chemical ways to convert CO₂ into hydrocarbons, the electrocatalytic coupling of water splitting and CO2 reduction appears attractive, as it is  a one-step process step, occurs at ambient  temperature and pressures, involves solely water and CO₂ as reactants, and may involve renewable electricity from wind, solar or hydro power plants.

CO₂ electroreduction is typically carried out on the surface of metal catalysts. Cu catalysts generate various gas products such as H₂, CO, methane and ethylene, while Au and Ag are the catalysts of choice for the selective electroreduction of CO₂ into CO/H2 synthesis gas mixtures. On all metal catalysts the CO₂ electroreduction suffers from prohibitively high kinetic overpotentials and limited product selectivity. This is why the identification of new catalysts or new catalyst formats, such as nanoparticles or core shell architectures, with reduced overpotentials combined with the exploration of new strategies to control and improve product selectivities has become the two key goals for CO₂ reduction.

In this contribution, we share recent work on the electroreduction of CO₂. In particular, we discuss a family of heteroatom-doped carbon catalysts for the generation of synthesis gas. We show evidence that carbon catalysts meet and exceed the activity and selectivity of traditional Au catalysts providing an intriguing cost-effective alternative.