Low‐Temperature CO2 Reduction using Mg–Ga Liquid Metal Interface

• Published in: Advanced materials interfaces Vol. 10; no. 3
• Main Authors: Ye, Linlin, Syed, Nitu, Wang, Dingqi, Guo, Jining, Yang, Jianing, Buston, Joshua, Singh, Ranjeet, Alivand, Masood S., Li, Gang Kevin, Zavabeti, Ali
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01-01-2023; Wiley-VCH
• Subjects: Carbon dioxide; carbon production; Carbon sequestration; Chemical reduction; CO 2 to carbon; Coking; Gallium; Liquid alloys; liquid metal alloy interfaces; Liquid metals; Magnesium; Mg recovery; Oxidation; Room temperature; room‐temperature CO 2RR
• ISSN: 2196-7350; 2196-7350
• DOI: 10.1002/admi.202201625

The need for effective and adaptive technologies for carbon dioxide (CO2) mitigation targeting global net‐zero carbon emissions is critically growing. Hence, innovative technologies for CO2 reduction have attracted worldwide interest from scientific research communities. The use of liquid metals for the conversion of CO2 into carbon or solid carbonaceous products has gained increasing attention in recent years due to their high activity and resistance to coking. Here, a facile approach for the reduction of CO2 to solid carbon using liquid Mg at and near room temperature, and atmospheric pressure is presented. In this process, magnesium (Mg) plays a major role in driving the dissociation of CO2 to its elemental constituents, carbon and oxygen. During the reaction process, Mg ions dissolve in gallium (Ga) liquid metal alloy, diffuse to the gas–liquid interface, and reduce CO2 to carbon while undergoing an oxidation reaction. The electrochemical method ensures a sustainable cyclic process by reducing Mg and Ga ions back to their metallic counterpart. The use of liquid metal alloys for CO2 reduction reactions can enable to achieve CO2 capture and storage at room temperature, setting a new foundation for the future exploration of efficient CO2 mitigation issues.
This work demonstrates a low temperature CO2 conversion to solid products using Mg–Ga liquid metal alloy. Magnesium metal in liquid form diffuses to the interface of liquid alloy and preferentially reacts with CO2 forming carbonous material and oxides. Oxides including MgO are converted back to Mg using a novel biphasic electrolysis presenting a sustainable platform for CO2 capture and conversion.