Enhanced plasma-driven H2S removal from natural gas via TiO2-coated dielectric surface modification

The efficient removal of H₂S impurities from natural gas is critical for improving gas quality and reducing maintenance costs. This study explores the integration of dielectric barrier discharge (DBD) plasma with TiO₂ to decompose H₂S effectively. Results show that the presence of TiO₂ significantly improve H₂S removal and energy efficiency compared with the plasma-only condition. However, the TiO₂-coated system achieves a much higher H₂S removal rate (5.4 mmol/h/g_TiO2), which was 27 times that of TiO₂-packed system, minimizing TiO₂ usage. Moreover, coated TiO₂ inhibits methane conversion, preserving the primary components of natural gas. Discharge analysis reveals that packing TiO₂ increases the reduced electric field and enhances mean electron energy, while coating further promotes filamentary discharge. Density functional theory (DFT) calculations confirm that defect-rich TiO₂, formed under plasma conditions, plays a crucial role in facilitating H₂S decomposition. A plausible reaction pathway for plasma-driven H₂S decomposition with coated TiO₂ is proposed. This study demonstrates the potential of DBD-coupled coated catalyst technology for efficient H₂S removal, offering a scalable solution for industrial gas purification.