Electrochemical Reactive Capture of Carbon Dioxide Using an Amine Sorbent and a Homogeneous Cobalt Electrocatalyst

The electrochemical reactive capture of CO2 (e-RCC) process, in which the capture of CO2 from industrial point sources is integrated with electrochemical conversion into valuable fuels and chemical feedstocks, is an ambitious technological frontier in energy science and industrial waste upcycling. We present an e-RCC system to capture and convert CO2 to CO using amines as sorbents and molecular cobalt electrocatalysts with pyridyldiimine-based ligands. Sparging dilute CO2 through water/acetonitrile electrolyte solutions containing n-butylamine and the cobalt catalyst enables the electroreduction of CO2 with enhanced activity and selectivity. Even at flue-gas concentrations of CO2 (5% v/v CO2, balance N2), the presence of n-butylamine in the electrolyte enables the reduction of CO2 to CO with 3-fold higher activity (TOFcat ∼3.3 × 104 s–1) compared to the catalyst system without amine. This study serves as a proof of concept for direct electrochemical reduction of CO2 from dilute streams using an amine-based e-RCC process.