Sub-Micrometric MCM-41 Particles as Support to Design Efficient and Regenerable Maghemite-Based Sorbent for H₂S Removal.

In this work, highly dispersed maghemite (λ-Fe₂O₃) in form of ultrasmall nanoparticles (about 2 nm) was embedded into a mesostructured silica MCM-41 (about 600 nm) featuring regular submicrometric hexagonal shaped particles via the two-solvent incipient wetness impregnation strategy. The obtained nanocomposite was then tested as H₂S sorbent in the mid-temperature range. When compared with a commercial sorbent (Katalko 32-5), it showed superior performances after the first sulfidation which remained steady over three repeated sulfidation cycles, highlighting the regenerability properties of the composite. In order to evaluate the effect of the length of the pore channels on the accessibility of H₂S to the active phase, an analogous micrometric λ-Fe₂O₃@MCM-41, featuring micrometric channels and particles of irregular shape was used as reference.