Effect of the Solvent on the Basic Properties of Mg–Al Hydrotalcite Catalysts for Glucose Isomerization

Suna An,Ji Chul Jung,Dahye Kwon,JeongHyun Cho

doi:10.3390/catal10111236

Abstract

We suggested the existence of a relationship between the base properties of Mg–Al hydrotalcite catalysts and the solvents employed in the industrially important isomerization of glucose produce fructose. We prepared Mg–Al hydrotalcite catalysts with different Mg/Al atomic ratios to tune the basic properties of the catalyst. The prepared catalysts were used in the glucose isomerization conducted in various solvents. Experimental results confirmed that the catalysts exhibited different activities in the different solvents. We also implemented the Hammett indicator method, which allows to analyze the basic properties of the catalysts in various solvents. According to evidence, the basic properties of the catalysts varied substantially in different solvents. Notably, increases in the catalysts’ base properties matched the observed increases in fructose yield of the glucose isomerization. Consequently, we suggested that, in order to prepare efficient Mg–Al hydrotalcite catalysts for glucose isomerization, the interaction between the solvent used to conduct the reaction and the basic properties of the catalyst, which are in turn influenced by the solvent, should be considered.

Highlights

The term biomass refers to plants that synthesize organic matter by exploiting solar energy and biological organisms, such as animals and microorganisms, which use plants as food
We suggested that, in order to prepare efficient Mg–Al hydrotalcite catalysts for glucose isomerization, the interaction between the solvent used to conduct the reaction and the basic properties of the catalyst, which are in turn influenced by the solvent, should be considered
We prepared a series of Mg–Al HT catalysts (HTX, X = 1.5, 2, 3, and 4) characterized by different Mg/Al atomic ratios (X) implementing the co-precipitation method; we used the prepared species to catalyze the fructose-producing glucose isomerization

Summary

Introduction

The term biomass refers to plants that synthesize organic matter by exploiting solar energy and biological organisms, such as animals and microorganisms, which use plants as food. Carbohydrates derived from biomass are the focus of considerable research interest as a resource that can be converted into valuable compounds [10,11,12,13]. The most abundant and inexpensive of carbohydrates, glucose, can be obtained by acid-saccharification or enzymatic saccharification of starchy and cellulosic. Glucose can in turn be converted into the expensive carbohydrate fructose through an isomerization assisted by a base catalyst. Fructose is switchable with dietary sugar for food applications, but with useful substances such as 5-hydroxymethylfurfural (HMF) and levulinic acid [14]. A reaction for producing fructose from glucose has been in the limelight, and studies on this transformation have been actively promoted [15,16,17,18,19,20]

Methods

Results

Conclusion