Syngas mercury removal using LaMeOx/ZSM-5 sorbents: Mechanistic insights and performance tests under industrial conditions

Effective elemental mercury (Hg 0 ) removal from syngas is essential for industrial mercury control. This study synthesized LaMeO x /ZSM-5 (Me = Zn, Cu, and Fe) sorbents via the sol–gel method and evaluated their Hg⁰ removal performance for simulated syngas at 50–250 °C. The physico-chemical properties of samples were characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), H 2 temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS). La 2 CuO 4 /ZSM-5 demonstrated superior efficiency (≥95 %) at 50–200 °C under simulated syngas, attributed to its porous structure and abundant surface-active oxygen. H 2 S significantly enhanced Hg 0 removal by forming active sulfur species, while H 2 , CO, and H 2 O inhibited performance due to competition for active sites. The inhibitory effects were mitigated by adding 500 ppm H 2 S. XPS and TPD analyses revealed HgS (cinnabar) as the dominant mercury species, with Cu 2+ ions and active oxygen critical for Hg 0 capture. Stability tests confirmed excellent reusability, with over 88 % efficiency maintained after 10 adsorption-regeneration cycles. La 2 CuO 4 /ZSM-5 emerges as a promising sorbent for Hg 0 removal, offering high efficiency, stability, and resistance to syngas components, making it suitable for industrial applications.