Au-Pd Bimetallic Nanocatalysts Incorporated into Carbon Nanotubes (CNTs) for Selective Oxidation of Alkenes and Alcohol

Hamed M Alshammari,Salma A Alzahrani,Abdullah S Alshammari,Hassan M A Hassan,Obaid F Aldosari,Jamal R Humaidi,Mosaed S Alhumaimess

doi:10.3390/pr8111380

Hamed M Alshammari, Salma A Alzahrani + Show 5 more

Open Access

https://doi.org/10.3390/pr8111380

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Abstract

Although supported bimetallic nanoparticles (Au-Pd NPs) demonstrate outstanding efficiency, challenges appear for carbon supported small and stable bimetallic nanoparticles used in liquid-phase reactions. In this work, Au-Pd NPs were supported on two types of carbon nanotubes: CNTs decorated covalently with carboxylic acid groups (O-CNTs) and non-covalently with the conductive poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer (P-CNTs). The Au-Pd NPs were prepared using the sol immobilization approach on the functionalized CNTs, and the effect of the utilized functionalization method on the properties of the immobilized metallic nanoparticles and the performance of the nanocomposite catalysts was investigated. The fabricated nanocomposites were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, High-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The catalytic performance of Au-Pd/O-CNTs and Au-Pd/P-CNTs was exploited for the oxidation of both cyclooctene and benzyl alcohol. Oxidation and polymer decoration directly led to an enhancement in the performance of CNTs catalysts. The nanocomposite catalyst with oxidized CNTs (Au-Pd/O-CNTs) was also found to be much more efficient and robust than that with polymer decorated CNTs (Au-Pd/P-CNTs). The enhancement in the oxidation of both cyclooctene and benzyl alcohol on Au-Pd/O-CNTs is attributed to the well-dispersed and smaller Au-Pd NPs as active sites on the surface of O-CNTs as compared to the P-CNTs surface.

Highlights

Controlled morphology and composition of the metallic and multimetallic nanomaterials have gained great interest due to of their exceptional catalytic efficiency in various fields including petroleum-refining substances, production of hydrogen and other various major chemical reactions [1,2,3,4].Among these metallic nanoparticles, gold and palladium have played a very important role in the catalysis processes [5,6]
The design of an efficient catalyst relies on the structure-performance relationship, the fabrication of the catalysts with well-defined structures and the factors that govern the catalytic performance of the synthesized catalyst [11,12,13]
We developed a facile and efficient approach to prepare bimetallic nanoparticle catalysts based on the functionalization of carbon nanotubes (CNTs) either by oxidation or by attaching a polymer chain

Summary

Introduction

Controlled morphology and composition of the metallic and multimetallic nanomaterials have gained great interest due to of their exceptional catalytic efficiency in various fields including petroleum-refining substances, production of hydrogen and other various major chemical reactions [1,2,3,4]. Among these metallic nanoparticles, gold and palladium have played a very important role in the catalysis processes [5,6]. Its capability of catalyzing the C-C bond formation and the stability of several

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Conclusion