Designing Electrode-Electrolyte Interfaces for Selective Carbon Dioxide Conversion

Abstract

Efficient electrochemical conversion of CO2 to fuels or stock chemicals with high-energy density would be a major step forward in the introduction of a carbon neutral energy cycle. Especially, understanding the role of electrocatalysts, supports, and electrolytes that can efficiently reduce CO2 to fuels with high selectivity is a subject of significant interest. Copper is the only known catalyst for producing a reasonable quantity of hydrocarbons, which means that designing proper electrode-electrolyte interfaces would modulate the catalytic reactivity and product selectivity. One of the representative observations on copper catalyst-electrolyte interface is that the selection of alkali cations has direct influence on activity and product selectivity; increasing the size of mono-valent cations can increase the activity and selectivity toward C-C coupled products by modulating the interaction energy between adsorbates and electric fields at the interface. Copper catalyst with a specific atomic-scale gap accelerates the reaction kinetics and selectivity to C2+ products. In addition, C-C coupling can be maximized by designing interfaces between copper and metal oxides. Therefore, designing electrode-electrolyte interface offers efficient, yet cheap electrochemical CO2 reduction systems.