Silica coated magnetic Fe3O4 nanoparticles supported phosphotungstic acid: a novel environmentally friendly catalyst for the synthesis of 5-ethoxymethylfurfural from 5-hydroxymethylfurfural and fructose

Abstract

In this study, a magnetically-recoverable catalyst (Fe 3 O 4 @SiO 2 -HPW) was prepared by the application of phosphotungstic acid (HPW) supported on silica-coated Fe 3 O 4 nanoparticles. The prepared samples were characterized by XRD, TEM, FT-IR, and N 2 -adsorption-desorption isotherms. The content of W in Fe 3 O 4 @SiO 2 -HPW was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and its surface acidity was determined by a potentiometric titration with n-butylamine. Fe 3 O 4 @SiO 2 -HPW showed an excellent catalytic activity for the synthesis of EMF from HMF and fructose. Under optimal reaction conditions, EMF was obtained in a high yield of 83.6% by the etherification of 5-hydroxymethylfurfural. EMF could also be synthesized directly from fructose in a yield of 54.8% via a one-pot reaction strategy. After reaction, the catalyst Fe 3 O 4 @SiO 2 -HPW could be easily separated from the reaction mixture with an external magnetic field, and it could be reused at least five times without any loss of its catalytic activity.Scheme 1 Synthesis of EMF from fructose in ethanol.

Single step synthesis, characterization and applications of curcumin functionalized iron oxide magnetic nanoparticles

“…A variety of stabilizing agents have also been reported in the literature being used for the coprecipitation of Fe 3 O 4 nanoparticles, allowing the introduction of additional functionality on the nanoparticle surface. 18–20 Such methodologies could modify the magnetic nanoparticle surface with exposed functional groups that could lead to the desired uniform dispersion of the particles in an aqueous environment and hence could be easily tailored for many potential applications. In reference to these systems, citrate-coated, dextran-modified, and self-assembled monolayer-coated Fe 3 O 4 MNPs have been prepared and find extensive application in biomedical, environmental, and catalysis field.…”

Insights into the Metal Salt Catalyzed 5-Ethoxymethylfurfural Synthesis from Carbohydrates

“…Due to its ease of separation from reaction mixture and reusability, much effort using heterogeneous catalyst has been taken to achieve the goal. For example, heteropolyacid [7,8] or its supported nanoparticles [9][10][11][12][13], acid-modified silica mesoporous materials [14,15], graphene oxide [16], and magnetic solid acid catalysts [11,17,18] were found to be efficient in the synthesis of EMF from fructose or fructose-based carbohydrates. By contrast, the transformation of glucose to EMF is much difficult owing to the demand of isomerization into fructose firstly, and the above developed catalysts had low reactivity.…”

Calcein-functionalized Fe3O4@SiO2 nanoparticles as a reusable fluorescent nanoprobe for copper(II) ion

“…The silica-coated magnetic nanoparticles were prepared by a modified Stöber method [30]. Briefly, 10 mL of the asprepared solution of magnetic nanoparticles was introduced into a 250-mL flask, and then 125 mL ethanol, 3 mL ammonia and 20 mL deionised water were added.…”