Development of Heterogeneous Olympic Medal Metal Nanoparticle Catalysts for Environmentally Benign Molecular Transformations Based on the Surface Properties of Hydrotalcite

Kiyotomi Kaneda,Takato Mitsudome,Koichiro Jitsukawa,Tomoo Mizugaki

doi:10.3390/molecules15128988

Abstract

In this review, we describe the development by our research group of highly functionalized heterogeneous Olympic medal metal (gold, silver, and copper) nanoparticle catalysts using hydrotalcite as a support, aimed towards Green and Sustainable Chemistry. Olympic medal metal nanoparticles can cooperate with the basic sites on the hydrotalcite surface, providing unique and high performance catalysis in environmentally-benign organic transformations such as aerobic oxidation of alcohols, lactonization of diols and selective deoxygenation of epoxides and nitro aromatic compounds.

Highlights

In designing heterogeneous catalysts, the creation of cooperative action between active metal species and an inorganic material support is a promising methodology for providing unique and highly active catalysis
We found that the particle size of Au nanoparticles could be controlled by selection of the reducing reagents used during preparation of the catalyst; the size of the gold nanoparticles decreased in order for the following reducing reagents: hydrazine >
For Au/TiO2, the addition of Na2CO3 as a base to the reaction mixture significantly improved the yield of acetophenone [15]. These results indicate that a concerted catalysis occurring between the base sites of the inorganic support and the Au nanoparticles is essential for achieving high catalytic activity in the oxidation of 1-phenylethanol

Summary

Introduction

The creation of cooperative action between active metal species and an inorganic material support is a promising methodology for providing unique and highly active catalysis. HT has attracted attention for adsorption and drug delivery applications, and for catalysis due to the following characteristics: (i) the cation-exchange ability of the brucite layer; (ii) the anion-exchange ability of the interlayer; (iii) the tunable basicity of the surface; and (iv) the adsorption capacity. We describe our recent research on the unique catalytic performance of hydrotalcite-supported Olympic medal metal (gold, silver, and copper) nanoparticles for various organic transformations. The concerted effect between the metal nanoparticles and the base sites of hydrotalcite leads to high performance heterogeneous catalysts

Oxidation of Alcohols

Basicity of HT

Selective Deoxygenation of Epoxides and Nitro Aromatic Compounds

Findings

Conclusions