Conversion of CO2 into fibrous carbon materials using Ga-based liquid alloys

• Published in: Journal of environmental chemical engineering 2024-06, Vol.12 (3), p.112721, Article 112721
• Main Authors: Cao, Xiaojing, Ma, Huanze, Liu, Weiming, Lu, Yongji, Yao, Shushen, Chang, Yanlong, Yang, Yangyang
• Format: Article
• Language: English
• Subjects: Adsorption kinetics; CO2 reduction; Fibrous carbon materials; Liquid alloy; Reaction kinetics
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2024.112721

This study investigates the catalytic reduction of CO2 using various ratios of Ga-based liquid alloys under different conditions. We explored the alloying of liquid gallium with metals like indium (In) and magnesium (Mg) through mechanical stirring and heating. The alloys, once prepared, were exposed to CO2 in a reactor, with the Ga-In-Mg alloy demonstrating optimal reaction effects. In an exemplary synthesis, 1 g of Ga was combined with 30 wt% In and 7 wt% Mg, yielding a 7 wt% Ga-In-Mg alloy. This alloy, when reacted with CO2 for 10 h, exhibited a maximum weight gain of 445 mg. Elemental analysis showed a carbon content increase from 4.56 % to 72.56 % post-reaction. The reacted alloy, post-acid washing and electron microscopy examination, revealed the production of fibrous carbon materials approximately 7 μm wide. The primary objectives of this research were to identify the optimal temperature for CO2 reduction by the alloy and to determine the most efficient alloy catalyst using orthogonal experimental methods. Furthermore, we aimed to elucidate the catalytic mechanism of gallium-based liquid metal in CO2 reduction. The study also involved analyzing the adsorption and reaction processes by fitting the adsorption and reaction kinetic curves of the liquid metal with CO2. Achieving these objectives could enable the conversion of CO2 into solid carbon products, aligning with current environmental and sustainable development goals. This research offers new insights and innovative approaches to tackling energy-related challenges, highlighting the potential of liquid metal alloys in carbon capture and reduction applications. •Investigation of CO2 thermal reduction using Ga-based liquid alloys.•The best alloy catalyst and the most suitable reaction conditions were determined.•The reaction kinetics and adsorption kinetics were investigated.•The reduced product contains fibrous carbon materials.