Selective Oxidation of Cinnamyl Alcohol to Cinnamaldehyde over Functionalized Multi-Walled Carbon Nanotubes Supported Silver-Cobalt Nanoparticles

Zahoor Iqbal,Helal F Hetta,Gaber El-Saber Batiha,Muhammad Sufaid Khan,Rozina Khattak,Muhammad Zahoor,Ivar Zekker,Tausif Iqbal,Eida M Alshammari

doi:10.3390/catal11070863

Abstract

The selective oxidation of alcohols to aldehydes has attracted a lot of attention because of its potential use in agrochemicals, fragrances, and fine chemicals. However, due to homogenous catalysis, low yield, low selectivity, and hazardous oxidants, traditional approaches have lost their efficiency. The co-precipitation method was used to synthesize the silver-cobalt bimetallic catalyst supported on functionalized multi-walled carbon nanotubes (Ag-Co/S). Brunauer Emmet Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD) were used to characterize the catalyst. For the oxidation of cinnamyl alcohol (CA) with O2 as an oxidant, the catalyst’s selectivity and activity were investigated. The impacts of several parameters on catalyst’s selectivity and activity, such as time, temperature, solvents, catalyst dosage, and stirring speed, were comprehensively studied. The results revealed that in the presence of Ag-Co/S as a catalyst, O2 could be employed as an effective oxidant for the catalytic oxidation of cinnamyl alcohol to cinnamaldehyde (CD) with 99% selectivity and 90% conversion. In terms of cost effectiveness, catalytic activity, selectivity, and recyclability, Ag-Co/S outperforms the competition. As a result, under the green chemistry methodology, it can be utilized as an effective catalyst for the conversion of CA to CD.

Highlights

The functional transformation of molecules to carbonyl compounds contributes significantly to the organic synthesis
The existence of silver, cobalt, carbon, and oxygen was confirmed in the elemental composition of the supported bimetallic nanoparticles, as shown in
The a>]. Silver-cobalt (Ag-Co)/S surface area measured by Brunauer Emmet Teller (BET) was 217.5 m2/g, which is consistent with the literature

Summary

Introduction

The functional transformation of molecules to carbonyl compounds contributes significantly to the organic synthesis. The carbonyl compound cinnamaldehyde is a significant chemical intermediate in organic transformations and has a wide range of applications in the food and fragrance industries. It is used in animal repellant, plant protection against nematodes, flea repellent, and antibacterial agent. The synthesis of metal catalysts for the catalytic the oxidation of target molecules in the presence of molecular oxygen as an oxidant has received more attention due to the atom economy and related environmental issues under the protocol of green chemistry. Bimetallic nanoparticles have received significant attention in comparison to monometallic particles because of their multifunctionalities, selectivity, and activity, and their use in a variety of research fields such as optics, water purification, electronics, and catalysis [2,3]. Hydrothermal reduction, sol-gel, and co-precipitation procedures have been used to prepare the bimetallic Ag-Co nanoparticles [6]

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Results

Conclusion