Anup K. Talukdar

HZSM-5 catalysed conversion of aqueous ethanol to hydrocarbons

Abstract The conversion of aqueous ethanol to hydrocarbons, over HZSM-5 of silica-alumina ratio 206 and 40, is described. The effect of temperature (673–773 K) on product distribution reveals definite trends. The yield and distribution of the products were influenced by catalyst-binder (alumina) composition, dilution of feed and the silica-alumina ratio of the catalyst. It is seen that light olefins can be obtained in good yield at high temperature, in absence of a binder, with dilution of the feed and with higher silica-alumina ratio.

Acetylation of phenol with Al-MCM-41

Abstract Mesoporous Al-MCM-41 molecular sieve materials with three different SiO2/Al2O3 ratios were used as catalysts for the acetylation of phenol with acetic anhydride and acetic acid as the acetylating agents. The reactions gave 100% ortho-selectivity with acetic acid being the more effective acylating agent. The reactions were run under different conditions of temperature, feed flow rate, reactant mole ratio and SiO2/Al2O3 ratio of the catalyst and all the variables were shown to have significant influence on the acetylation of phenol. A possible reaction mechanism is also suggested.

1-Hexene isomerization and n-hexane cracking over HMCM-22

Abstract Isomerization of 1-hexene and cracking of n -hexane over HMCM-22 were carried out in a continuous flow glass reactor. The results were compared with those obtained over HZSM-5 under similar conditions of conversion. The catalyst HMCM-22 caused much more double bond shift and less skeletal isomerization in 1-hexene isomerization than HZSM-5. Also, in n -hexane cracking, HMCM-22 gave a higher yield of olefins and a lower yield of aromatics than HZSM-5. The results can be explained on the basis of the lower acidic strength and the inferior hydrogen transfer capacity of HMCM-22 compared to those of HZSM-5.

Oxidation of anisole over MCM-48 materials modified by incorporation of transition and inner transition metals

Aluminosilicates with well-ordered MCM-48 mesostructures were synthesized by one step and two step methods. Single step method was found to be appropriate for metal incorporation. This method was applied to synthesize transition and inner transition metal incorporated MCM-48. These modified MCM-48 materials were characterized by a variety of techniques including XRD, FTIR, DRS-UV-Vis, TGA, N2 adsorption and SEM. Post-synthesis modification of the SiMCM-48 material was also done by impregnating 1%, 3% and 5% vanadium without compromising the integrity of the cubic mesostructure. The transition and inner transition metal incorporated MCM-48 materials were tested for oxidation reaction and were found to exhibit far better activities in anisole oxidation than SiMCM-48. Among the metal introduced MCM-48, vanadium–MCM-48 samples showed highest activities.

Removal of Cu(II) and Pb(II) from Aqueous Solutions Using Nanoporous Materials

The present work deals with the adsorption of Cu2+ and Pb2+ on zeolites (ZSM-5, mordenite) and mesoporous materials (MCM-48, MCM-41). The characterization of the synthesized samples was performed by means of XRD, SEM, and thermogravimetric analysis. The batch method was employed to study the influence of adsorbent nature, contact time, initial metal ion concentration, and adsorbent load. The adsorption on MCM-48 follows a pseudo-second-order kinetic model. This material was found to be more effective for the removal of lead in a batch process as compared to the other adsorbents and the removal efficiency of the materials for Pb(II) followed the order MCM-48 > mordenite > ZSM-5 > MCM-41 and that for Cu(II) followed the order ZSM-5 > mordenite > MCM-41 > MCM-48.

A study on the synthesis, characterization and catalytic activity of ruthenium-substituted MFI (Mobil Five) zeolite

Hydrothermal synthesis was adapted to prepare a series of ruthenium (Ru)-incorporated Mobil Five (MFI) zeolite materials with silicon (Si) to aluminium (Al) ratio of 100 and with Al to Ru ratios 1:1, 2:1 and 3:1. An X-ray diffractometer (XRD) and FT-IR were employed to identify the formation of the zeolite phase. A favourable environment was maintained in the gel to overcome the difficulties of isomorphous substitution of ruthenium into the MFI framework. The unit cell volume change and the shift in XRD reflection positions showed a positive correlation with increased ruthenium content in the samples. UV–Vis (DRS) spectra confirmed the position of ruthenium in the T-site in the MFI structure. Thermogravimetric analysis was carried out for studying water and template removal patterns and also for studying the thermal stability of the synthesized samples. Formation of uniform rectangle- and twinned-rectangle-shaped MFI particles with particle size approaching

An efficient synthesis of nanocrystalline MFI zeolite using different silica sources: A green approach

27\,\upmu \hbox {m}

Synthesis and characterization of isomorphously zirconium substituted Mobil Five (MFI) zeolite

27μm was confirmed by scanning electron microscopy. Energy-dispersive X-ray analysis was carried out for quantification of Si, Al and Ru. The catalytic activities of the synthesized samples for the hydroxylation of phenol was investigated, the major products being catechol and hydroquinone.