Integrated Electrochemical Carbon Capture and Utilization by Redox‐Active Amine Grafted Gold Nanoparticles

Abstract

Electrochemical carbon capture and utilization (eCCU) from flue gas CO2 could avoid high energy consumption and capital input in conventional capture, storage, and utilization, which is a promising approach for achieving negative emissions and producing “e‐chemicals.” However, low CO2 concentration and leftover O2 in the flue gas presumably lowers the eCCU performance. Herein, redox‐active 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole (AMT) functionalized gold nanoparticles are synthesized to achieve integrated electrochemical capture and reduction of CO2 in simulated flue gas (SFG, 15% CO2, 4% O2, balanced with N2), achieving maximum CO Faradaic efficiency of 80.2% at −0.45 V versus RHE in H‐type cell, and 66.0% at voltage of 2.7 V in a full cell, respectively. The AMT ligand can capture CO2 by strong interaction with CO2 in the reduced state and serve as a selective layer to suppress O2 reduction, which provides the ability of electrochemical carbon capture from SFG and significantly decreases energy required for CO2 electro‐reduction.

Correlating the Structure of Quinone-Functionalized Carbons with Electrochemical CO2 Capture Performance

“…4,5 Electrochemical carbon capture has been implemented using a range of approaches including supercapacitive swing adsorption (SSA), 6,7 pH swing, [8][9][10] and with redox-active molecules that directly capture CO2 following electrochemical reduction. [11][12][13] The most common class of redox-active molecules used in the direct electrochemical carbon capture approach are quinones. The use of quinone molecules for carbon capture has had large popularity due to their reversible redox activity, stability and ease of tuneability.…”