Magnetically Modified Al₂O₃ Pillared Clays

Abstract

Surface modification of alumina pillared montmorillonite with magnetic iron oxide nanoparticles has been achieved by using as precursor a colloidal solution of magnetite in poly(vinyl alchohol). Two synthetic routes were developed differing in the number of steps. The magnetic and adsorption properties of the modified products were studied using Mo ¨ssbauer spectroscopy, magnetization, and surface area measurements. All measurements showed that their magnetic and adsorption properties depend on the way of preparation. The Mo ¨ssbauer spectra exhibited different superparamagnetic behavior for each modified product, whereas sorption analysis gave different surface areas and structural characteristics. TEM reveals the nano size of the iron oxides and furthermore their random dispersion at the external surfaces of the clay.

Molybdenum modified Montmonrillonite clay as an efficient catalyst for low temperature NH3‐SCR

“…33 When comparing Al-PILC and Al-PILC-MnCe, the (001) and (100) peaks remained in the Al-PILC but not in Al-PILC-MnCe, indicating the layered structure was maintained after Al-intercalation however MnCe-loading caused structure collapse. 2,[34][35][36][37] Al-, Zr-, AlZr-PILCs as the catalyst supports Based on the previous results, Al-PILC showed increased surface area and better porosity. Mt was further process into Zr-PILC and AlZr-PILC to search an optimized catalyst support.…”

“…The small peak observed at 2θ = 9° for Al‐PILC could be suggesting a very small fraction of the clay was not pillared . When comparing Al‐PILC and Al‐PILC‐MnCe, the (001) and (100) peaks remained in the Al‐PILC but not in Al‐PILC‐MnCe, indicating the layered structure was maintained after Al‐intercalation however MnCe‐loading caused structure collapse …”

“…Al‐PILC‐MnCe, Zr‐PILC‐MnCe and AlZr‐PILC‐MnCe sample had similar N 2 selectivity rate between 95 to 70%, all of which were much higher than that of the Clay‐MnCe. This could partially owing to the fact that ZrO 2 could improve porosity, surface acidity, the lattice oxygen mobility and reactivity, moreover, Zr species could interact with the active metallic components causing the change of electronic structure and oxidative states of the catalyst …”

“…This could partially owing to the fact that ZrO 2 could improve porosity, surface acidity, the lattice oxygen mobility and reactivity, moreover, Zr species could interact with the active metallic components causing the change of electronic structure and oxidative states of the catalyst. 33,34 XRD, BET were employed to reveal structural-activity relationship. In Table 2, Al-PILC and AlZr-PILC showed increased S BET value of 266 and 162 m 2 ·g −1 comparing with that of the original Mt, illustrating Al/Zr pillars successfully inserted into the interlayer structure of the clay.…”

The Role of the Nature of Pillars in the Structural and Magnetic Properties of Magnetic Pillared Clays

“…Relatively few studies of magnetic pillared clays have been carried out to date (Skoutelas et al, 1999;Bachir et al, 2009;Yu and Yang, 2010). The performance of the magnetically modified Fe-pillared clay mineral was evaluated by adsorption of methyl orange and, intensified separation by means of an external magnetic field.…”