Sustainable iron production via highly efficient low-temperature electrolysis of 3D conductive colloidal electrodes

Abstract

Towards decarbonizing the carbothermic reduction of iron and steelmaking, which produces around 5% of global CO₂ emissions, we herein propose a low-temperature electrolysis (100 °C) with 3D electrically–ionically conductive colloidal Fe₂O₃ electrodes as a novel and sustainable alternative. With the designed electrodes that offer a 3D conductive network to facilitate the electrochemical reduction of Fe₂O₃ at such a low temperature, high-purity Fe powder (>95%) can be produced with high current efficiency (>95%) and no direct CO₂ emission. In addition to Fe, we also demonstrate the production of metal and alloy powders such as Cu, Ag, and an FeNi alloy using the proposed method. A techno-economic assessment of the process is performed to evaluate industrial feasibility as well as CO₂ emission analysis. Altogether, this alternative process is green, environmentally friendly, and energy efficient, showing great potential for revolutionizing the conventional process that has had a significant environmental impact for decades.