A Near-Infrared Colorimetric Fluorescent Probe for Ferrous Ion Detection and Imaging

Based on the N-redox mechanism, a turn-on near-infrared fluorescence probe (SWJT-15) with cyano isophorone as skeleton was designed and synthesized for the detection of ferrous ions (Fe2+). The probe has a lower detection limit (83 nM) and fast response (200 s) to Fe2+ ions. And the probe has unique selectivity and good anti-interference performance against Fe2+ ions compared to other metal ions. Moreover, the probe has been successfully applied to imaging Fe2+ ions in HeLa cells.

A selective and stable Fe/TiO2 catalyst for selective hydrogenation of butadiene in alkene-rich stream

The replacement of precious metals by more abundant and therefore much less expensive metals remains a very important challenge in catalysis. A Fe/TiO2 catalyst prepared by deposition-precipitation with urea showed very high selectivity to alkenes (>99%), even at high conversion (>90%), in selective hydrogenation of butadiene in an excess of propene. Its activity is very stable at 175 °C whereas the catalyst deactivates at 50 °C, although it is also initially very active. The presence of metallic iron seems to be necessary to ensure these excellent performances.

Stability of Colloidal Iron Oxide Nanoparticles on Titania and Silica Support

Using model catalysts with well-defined particle sizes and morphologies to elucidate questions regarding catalytic activity and stability has gained more interest, particularly utilizing colloidally prepared metal(oxide) particles. Here, colloidally synthesized iron oxide nanoparticles (Fe _x O _y -NPs, size ∼7 nm) on either a titania (Fe _x O _y /TiO₂) or a silica (Fe _x O _y /SiO₂) support were studied. These model catalyst systems showed excellent activity in the Fischer-Tropsch to olefin (FTO) reaction at high pressure. However, the Fe _x O _y /TiO₂ catalyst deactivated more than the Fe _x O _y /SiO₂ catalyst. After analyzing the used catalysts, it was evident that the Fe _x O _y -NP on titania had grown to 48 nm, while the Fe _x O _y -NP on silica was still 7 nm in size. STEM-EDX revealed that the growth of Fe _x O _y /TiO₂ originated mainly from the hydrogen reduction step and only to a limited extent from catalysis. Quantitative STEM-EDX measurements indicated that at a reduction temperature of 350 °C, 80% of the initial iron had dispersed over and into the titania as iron species below imaging resolution. The Fe/Ti surface atomic ratios from XPS measurements indicated that the iron particles first spread over the support after a reduction temperature of 300 °C followed by iron oxide particle growth at 350 °C. Mössbauer spectroscopy showed that 70% of iron was present as Fe²⁺, specifically as amorphous iron titanates (FeTiO₃), after reduction at 350 °C. The growth of iron nanoparticles on titania is hypothesized as an Ostwald ripening process where Fe²⁺ species diffuse over and through the titania support. Presynthesized nanoparticles on SiO₂ displayed structural stability, as only ∼10% iron silicates were formed and particles kept the same size during in situ reduction, carburization, and FTO catalysis.

Hydrothermal preparation of Fe–Zr catalysts for the direct conversion of syngas to light olefins

Two-step hydrothermal preparation of Fe/Zr–K catalysts could improve the olefin selectivity and product distribution by reducing the secondary hydrogenation ability and suppressing the formation of heavy hydrocarbons during CO hydrogenation.

Mechanistic study of CO formation from CO2 using a mixed-metal oxide of tin, iron, and aluminum

CO formation from CO₂ using a mixed-metal oxide of tin, iron, and aluminum.

Radioisotopic study of11C-labelling methanol decomposition on iron oxide modified mesoporous MCM-41 silica

Novel11C-radiolabelling method was applied for the investigation of methanol conversion on iron oxide modified mesoporous MCM-41. Changes in the selectivity were observed varying the state of the loaded iron species or the degree of the surface coverage with11C-radiolabelling methanol. Combining the Moessbauer spectroscopy, X-ray diffraction (XRD), N2-physisorption, and temperature-programmed reduction- thermogravimetric (TPR-TG) techniques with the high sensitive11C-radioisotopic catalytic analysis, the contribution of the different reaction pathways of methanol conversion was discussed.