Enhancing three-way reforming in a blast furnace: insights into the effects of hexagonal boron nitride addition on Ni-Cu-based catalysts with different supports and their reaction mechanisms

The steelmaking industry is one of the largest sources of CO₂ emissions, highlighting the urgent need for effective greenhouse gas reduction strategies. This research successfully developed innovative catalysts that integrate the reverse water–gas shift (RWGS) reaction and dry reforming of methane (DRM) to enable a three-way reforming process, utilizing CO₂, CH₄, and H₂ as reaction gases or coke oven gas (COG) as a feedstock. Notably, it demonstrates a near-complete direct CO₂ reduction from COG. Catalytic performance was optimized by evaluating supports (MgAl₂O₄, hydrotalcites (MG30, MG70), SiO₂, and ZSM-5), metals/metal oxide loadings (Ni, Cu, Ni-Cu), and hexagonal boron nitride (h-BN). Additionally, the catalysts were characterized to elucidate their morphology, structure, and thermal stability. The 8Ni-2Cu/10h-BN.MG30 catalyst exhibited exceptional catalytic performance, achieving high CO₂, and CH₄ conversion rates with remarkable CO space–time yield (3328.7 mg g_cat⁻¹ h⁻¹). Incorporating h-BN enhanced stability, mitigating coke formation and deactivation, while COG proved to be an effective feedstock. Experiments and theory were also designed to understand the reaction mechanism further. The findings confirm that H-induced CO₂ decomposition is the primary pathway for CO₂ dissociation, where adsorbed H* species preferentially interact with CO₂* in the gas phase, facilitating efficient conversion. This work highlights three-way reforming as a promising approach for reducing carbon emissions and enhancing by-product gas utilization, marking a significant step toward sustainable steel production.