The effect of synthesis method and post-synthesis treatment on the formation of neutral Mn(II) complex into anionic zeolite structure and investigation of its catalytic activity in the epoxidation of alkenes

Maryam Moosavifar,Nasrin Nouruzi,Hossein Mahmoodi,Mohammad Reza Marefat,Abdolali Alemi

doi:10.1007/s13738-014-0427-5

Maryam Moosavifar, Nasrin Nouruzi + Show 3 more

Open Access

https://doi.org/10.1007/s13738-014-0427-5

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Abstract

In this study, we improved the catalytic performance of manganese porphyrin encapsulated HY zeolite for alkene epoxidation reaction. For this purpose, Manganese tetra pyridyl porphyrin encapsulated into modified dealuminated Y zeolite (MnTPP-MDAZY) was synthesized using zeolite template synthesis method. This heterogenized catalyst was characterized by FT-IR, UV–Vis, XRD and atomic absorption spectra (AAS) technique. Catalyst loading was 0.263 mmol/g support. In this way, high catalyst loading is probably related to the decrease of the size of metalloporphyrin and the post-synthesis treatment. The latter one causes the increase of the diameter of the mesoporous structure as a result of the dealumination of zeolite with EDTA treatment. High catalyst loading efficiently enhances the epoxidation of alkenes.

Highlights

IntroductionIn the post-synthesis treatment, secondary mesoporous structure is formed using the dealumination of zeolite [7, 10, 15,16,17]
Zeolite-encapsulated metal complexes have attracted special attention as modern catalytic systems and as model compounds for enzyme mimicking [1]
In this study, we improved the catalytic performance of manganese porphyrin encapsulated HY zeolite for alkene epoxidation reaction

Summary

Introduction

In the post-synthesis treatment, secondary mesoporous structure is formed using the dealumination of zeolite [7, 10, 15,16,17] It leads to high Si/Al ratio and the replacement of large macromolecules such as porphyrin in the supercage of zeolite becomes possible [18]. The dealuminated sample was washed with hot distilled water dried and was used in the synthesis of manganese porphyrin inside nanocage of zeolite [22]. To prepare manganese tetra pyridyl porphyrin in the supercages of zeolite, 900 ll (equal 0.873 g) pyrrol, 1,320 ll (equal 1.386 g) fresh distilled benzaldehyde and 2 g MDAZY were mixed in 50 ml with propionic acid according to the reported procedure (Scheme 1) [22]. The crude filtrates were purified on a silicagel plate or a silica-gel column and identified by IR and 1H NMR spectral data

Result and discussion

Findings

Conclusion