Chemical trapping of gaseous H2S at high and low partial pressures by an iron complex immobilized inside the montmorillonite interlayer

• Published in: Microporous and mesoporous materials Vol. 265; pp. 8 - 17
• Main Authors: Malferrari, Daniele, Castellini, Elena, Bernini, Fabrizio, Rubio, Aida Serrano, Castro, German Rafael, Sainz-Díaz, Claro Ignacio, Caleffi, Matteo, Brigatti, Maria Franca, Borsari, Marco
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.07.2018
• Subjects: Gas trapping; Hybrid material; Hydrogen sulphide; Iron; Montmorillonite; Hydrogen sulphide; Iron; Montmorillonite; Gas trapping; Hybrid material
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2018.01.017

A stable hybrid material (Mt-Fe(III)Phen) formed by intercalation of the μ-oxo Fe(III)-phenanthroline complex [(OH2)3(Phen)FeOFe(Phen)(OH2)3]4+ (Fe(III)Phen) in montmorillonite (Mt) is able to immobilize H2S in gaseous phase with high efficiency even at extremely low pressures. DR UV–vis and I.R. spectroscopies, elemental analysis, X-ray powder diffraction, thermal analysis coupled with evolved gas mass spectrometry, and X-ray absorption spectroscopy show that the material has high adsorption capacity, performs fast H2S trapping and is long-lasting. Moreover, even extremely low levels of H2S can be removed easily and quickly from gaseous phase using a suitable amount of the trapping material. The immobilization mechanism likely involves a redox reaction between iron (III) and one S2− ion, followed by the binding of a second S2− ion to the metal centre. The process takes place at room temperature, is reversible for several cycles, and does not require pre-treatment of neither gaseous H2S nor the adsorbent material. Therefore, this modified montmorillonite is a promising material to get rid of H2S in processes of environmental interest and to obtain gaseous (and gasifiable) high quality hydrocarbons in fuels refineries. [Display omitted] •The Mt-Fe(III)Phen hybrid material works as an efficient trap for gaseous H2S.•The process takes place easily at room temperature and is reversible.•Trapping of H2S involves a redox reaction and the formation of a Fe(II)-S bond.•Mt-Fe(III)Phen exhibits strong ability to trap H2S even at very low partial pressure.