Heterogeneous Nb-containing catalyst/N,N-dimethylacetamide-salt mixtures: novel and efficient catalytic systems for the dehydration of fructoseElectronic supplementary information (ESI) available. See DOI: 10.1039/c6ra09664f

• Main Authors: Xue, Zhimin, Cao, Bobo, Zhao, Wancheng, Wang, Jinfang, Yu, Tingting, Mu, Tiancheng
• Format: Journal Article
• Published: 06.07.2016
• ISSN: 2046-2069
• DOI: 10.1039/c6ra09664f

The development of efficient catalytic systems for the dehydration of carbohydrates to produce 5-hydroxymethylfurfural (HMF) is a very attractive topic. In this work, we synthesized a novel Nb-containing catalyst by the reaction of niobium chloride and nitrilotris(methylenephosphonic acid) (NTMPA), denoted as Nb-NTMPA. The synthesized Nb-NTMPA was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, and Fourier transform infrared spectroscopy and used as the heterogeneous catalyst for the dehydration of fructose into HMF using the mixture of N , N -dimethylacetamide (DMA) and salts as the reaction solvent. It was found that Nb-NTMPA was very active for the reaction and a HMF yield of 85.6% could be achieved in a DMA-NaBr mixture under the optimal reaction conditions. Further study indicated that the salts could affect the activity of the reaction systems by the formation of DMA·M + (M = Li, Na and K) macrocations and weakly ion-paired halide ions. Moreover, Nb-NTMPA/DMA-salt systems could also be used in the production of HMF from inulin and sucrose with satisfactory yields. Heterogeneous Nb-containing catalyst/ N , N -dimethylacetamide-salt mixtures could be used as an efficient catalytic system for the dehydration of fructose to produce 5-hydroxymethylfurfural.