Electrified Carbon Cycling for Neutralizing the Steelmaking Industry

Abstract

The conventional steelmaking process emits 1.8 tons of CO₂ to produce 1 ton of crude steel, making the steel industry the world's largest emitting manufacturing sector. Here, we propose and demonstrate a renewable route based on electrified carbon cycling, which significantly reduces CO₂ emission by 83%. The critical step of the route involves electrochemical CO₂ reduction (CO₂RR) to produce CO-rich syngas, which reduces iron ore into metallic iron (Fe_xO_y-to-Fe), effectively closing the carbon cycling. A technoeconomic analysis (TEA) reveals that the energy efficiency of this novel process is dependent on the operating parameters of CO₂RR, with optimal efficiency occurring at the current density range of 150-200 mA cm⁻². As a proof-of-concept study, sulfur vacancy (V_S)-engineered Ag₃CuS₂ was developed as a high-performance CO₂RR electrocatalyst. This catalyst yields a CO-rich syngas at a high Faradaic efficiency (FE) close to 100% at a cell voltage of 2.5 V. The CO₂RR-produced syngas effectively reduced iron oxide into metallic iron. The implementation of electrified carbon cycling significantly increases the utilization of electricity in steel production, reaching 88.7%. This research describes a sustainable way to reshape the ironmaking process and ultimately neutralize the steel industry.

Keywords

carbon-neutral / CO₂RR / electrocatalysts / renewable energy / steelmaking

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RIGHTS & PERMISSIONS

2025 The Author(s). Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.