Fe@Hierarchical BEA Zeolite Catalyst for MW-Assisted Alcohol Oxidation Reaction: A Greener Approach

Marta Andrade,Armando Pombeiro,Angela Martins,Leonardo Ansari,Ana Carvalho,Luísa Martins

doi:10.3390/catal10091029

Marta Andrade, Armando Pombeiro + Show 4 more

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https://doi.org/10.3390/catal10091029

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Abstract

The aim of this study was to investigate the catalytic activity of hybrid materials of iron supported on hierarchical zeolites in the oxidation reaction of 1-phenylethanol to acetophenone. A greener approach was considered for the preparation of the catalyst and performance of the oxidation reaction. Hierarchical BEA zeolite samples were obtained from an alkaline and a subsequent acid treatment. The materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen adsorption at −196 °C. An iron salt was incorporated onto the hierarchical zeolites by mechanochemical grinding and the catalytic performance of the prepared materials was evaluated towards the microwave assisted oxidation reaction of 1-phenylethanol. The catalyst obtained by Fe immobilization on sample modified by 0.2 M NaOH followed by acid treatment (Fe@BEA0.2AT) is the most promising material with 35% yield and 56% selectivity to acetophenone, allowing five reuse cycles without significant loss of activity and selectivity.

Highlights

The selective oxidation of alcohols to targeted carbonyl-containing compounds is among the central reactions in organic chemistry, with a pivotal role at industrial level, attracting a great attention for the development of environmentally friendly processes and sustainable production of novel materials and energy sources [1,2,3].Even though some remarkable advances have been accomplished, only a few known catalytic systems are able to offer both economic and practical oxidation approaches toward industrially significant transformations
BEA zeolite was modified through alkaline treatments followed by an acid treatment
2 O) incorporated and modified samples were functionalized with an iron salt (FeCl2·4H2O) incorporated by ball milling

Summary

Introduction

The selective oxidation of alcohols to targeted carbonyl-containing compounds is among the central reactions in organic chemistry, with a pivotal role at industrial level, attracting a great attention for the development of environmentally friendly processes and sustainable production of novel materials and energy sources [1,2,3].Even though some remarkable advances have been accomplished, only a few known catalytic systems are able to offer both economic and practical oxidation approaches toward industrially significant transformations. The selective oxidation of alcohols to targeted carbonyl-containing compounds is among the central reactions in organic chemistry, with a pivotal role at industrial level, attracting a great attention for the development of environmentally friendly processes and sustainable production of novel materials and energy sources [1,2,3]. Many of the found methods present several drawbacks, as high reagent cost, instability, use of hazardous metals or oxidants, harsh reaction conditions, operational complexity, low selectivity and low yields, requirement of additives/co-catalysts, or huge production of wastes [3]. Synthetic limitations have been encountered, with their synthesis involving considerable work (multiple steps) and limited yields. To overcome such challenges, there is a continuing pursuit for innovative catalytic systems.

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