Maity, Sudip and Saha, Sujan (2016) MnOx supported on a TiO2@SBA-15 nanoreactor used as an efficient catalyst for one-pot synthesis of imine by oxidative coupling of benzyl alcohol and aniline under atmospheric air. RSC Advances , 6 (77). pp. 73906-73914.
Full text not available from this repository.Abstract
In the present study, a mesoporous silica (SBA-15) encapsulated TiO2 nanoreactor is used as a support for MnOx and this MnOx/TiO2@SBA-15 acts as a catalyst for the one-pot synthesis of imine by oxidative coupling between benzyl alcohol and aniline in the presence of atmospheric air. To understand the properties, the catalysts were characterized by several analytical techniques, namely, N2 adsorption–desorption isotherm, small angle X-ray scattering (SAXS), wide angle X-ray diffraction, high resolution transmission electron microscopy (HRTEM), H2-temperature programmed reduction (H2-TPR), O2-temperature programmed oxidation (O2-TPO) and NH3-temperature programmed desorption (NH3-TPD). The pore encapsulation process by SBA-15 causes TiO2 to be in a highly dispersed state, and this highly dispersed TiO2 makes maximum contact with the MnOx species as well as the reactant molecules. The reaction was carried out at atmospheric pressure with equimolar amounts of substrates without additives in the presence of atmospheric air. The yield and selectivity of imines vary with the MnOx and TiO2 loading. The 7.5 wt% MnOx loaded TiO2@SBA-15 (5 wt% TiO2) nanoreactor showed the highest catalytic activity. With the increase in weak acid sites and the oxygen activation ability of the prepared catalyst, the conversion and selectivity of the desired product reached 96% and 97%, respectively. The investigation of the reaction mechanism suggests that there is a synergistic effect between highly dispersed TiO2 and MnOx, which improves the reactant conversion and the selectivity of the desired product (N-benzylideneaniline) and also the prepared catalyst shows excellent recyclability up to the 10th cycle. The recyclability and hot filtration study confirms the true heterogeneity of the prepared catalyst during imine synthesis. The heterogeneity of the prepared catalyst, the avoidance of any noble metal and the utilization of air as an oxidizing agent represent an efficient, green reaction pathway for imine synthesis.
| Item Type: | Article |
|---|---|
| Subjects: | Coal Gesification |
| Divisions: | UNSPECIFIED |
| Depositing User: | Mr. B. R. Panduranga |
| Date Deposited: | 20 Mar 2018 11:03 |
| Last Modified: | 20 Mar 2018 11:03 |
| URI: | http://cimfr.csircentral.net/id/eprint/1890 |
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