Issue 7, 2016

Selective oxidation of 5-hydroxymethylfurfural with H2O2 catalyzed by a molybdenum complex

Abstract

Organic solvent free 5-hydroxymethylfurfural (HMF) oxidation into 2,5-furandicarboxylic acid (FDCA) with hydrogen peroxide using quaternary ammonium octamolybdate and quaternary ammonium dectungstate was studied. Tetra-1-ethyl-3-methylimidazolium octamolybdate ([EMIM]4Mo8O26), tetra-hexadecyltrimethyl ammonium octamolybdate ([CTAB]4Mo8O26) and tetra-ethylpyridinium octamolybdate ([EPy]4Mo8O26) displayed high activity for the selective oxidation of HMF to FDCA, and the selectivity of FDCA could reach 100% with a 99.5% conversion of HMF in the presence of [EMIM]4Mo8O26. The byproduct formed in competition with FDCA was identified as the intermediate 5-hydroxymethyl-2-furan carboxylic acid (HMFCA) and 5-formyl-2-furan carboxylic acid (FFCA), and neither 2,5-diformyl furan (DFF) nor any other byproducts from the oxidative cleavage of the HMF furan ring were detected during the oxidation process, which indicated that the aldehyde group of HMF oxidizes first, followed by the oxidation of the hydroxymethyl group in this reaction system. Although the quaternary ammonium salts, such as [EMIM]Br, EPyBr and CTAB, prevented FDCA formation from the HMFCA advanced oxidation, they could eliminate the oxidative cleavage of the furan ring and improve the affinity of HMF and catalysts, to make the catalytic active centers readily accessible to HMF molecules. However, tetra-1-ethyl-3-methylimidazolium dectungstate ([EMIM]4W10O32), tetra-hexadecyltrimethyl ammonium dectungstate ([CTAB]4W10O32) and tetra-ethylpyridinium dectungstate ([EPy]4W10O32) were unfavorable for FDCA formation. The great difference in performance of quaternary ammonium octamolybdate and quaternary ammonium dectungstate in HMF oxidation with H2O2 was attributed to their different structure.

Graphical abstract: Selective oxidation of 5-hydroxymethylfurfural with H2O2 catalyzed by a molybdenum complex

Supplementary files

Article information

Article type
Paper
Submitted
24 Aug 2015
Accepted
19 Nov 2015
First published
09 Dec 2015

Green Chem., 2016,18, 2122-2128

Author version available

Selective oxidation of 5-hydroxymethylfurfural with H2O2 catalyzed by a molybdenum complex

S. Li, K. Su, Z. Li and B. Cheng, Green Chem., 2016, 18, 2122 DOI: 10.1039/C5GC01991E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements