Selective Conversion of Glucose to 5-Hydroxymethylfurfural by Using L-Type Zeolites with Different Morphologies

María José Ginés-Molina , Nur Hidayahni Ahmad (1) , Sandra Mérida-Morales , Cristina García-Sancho , Svetlana Mintova (2) , Eng-Poh Ng (3) , Pedro Maireles-Torres

1 University of Hail
2 LCS - Laboratoire catalyse et spectrochimie
3 LMPC - Laboratoire de Matériaux à Porosité Contrôlée

The catalytic dehydration of glucose to 5-hydroxymethuylfurfural (HMF) requires the development of selective solid acid catalysts, bearing different types of acid-base active sites. In the present work, the morphology of an L-type zeolite (LTL topology) has been modified in order to evaluate the influence of several protonated-form LTL zeolites with different morphologies on their stability and catalytic performance in glucose conversion to 5-HMF. Physico-chemical characterisation of LTL-based catalysts has revealed that the three types of morphologies (needle, short rod and cylinder) are active, with complete glucose conversion and high HMF yield values. The addition of CaCl2 had a positive influence on the catalytic performance, improving the partition coefficient in the biphasic water:methyl isobutyl ketone system for efficiently extracting HMF formed from the aqueous phase. It was found that 2 morphology influences the textural and acid properties of LTL zeolites, and hence their catalytic performance. The best catalytic results have been obtained with the NEEDLE-LTL, showing nanoparticles with a length of 4.03 nm and a width of 0.63 nm, which attains a HMF yield of 63.1%, at 175 ºC after 90 min of reaction, and a glucose conversion of 87.9%. The reusability study has revealed a progressive decrease in HMF yield after each catalytic cycle. Different regeneration methods have been essayed (washing with solvents and calcination), without recovering the initial catalytic activity. The presence of organic molecules in the micropores has been demonstrated by TG-DTA analysis, which are difficult to remove even after a regeneration process at 550 ºC.

Mots clés: biomass; glucose; 5-hydroxymethylfurfural; LTL zeolite; heterogeneous catalysis

Domaines: Chimie

María José Ginés-Molina, Nur Hidayahni Ahmad, Sandra Mérida-Morales, Cristina García-Sancho, Svetlana Mintova, et al.. Selective Conversion of Glucose to 5-Hydroxymethylfurfural by Using L-Type Zeolites with Different Morphologies. Catalysts, 2019, 9 (12), pp.1073. ⟨10.3390/catal9121073⟩. ⟨hal-02893855⟩