Towards industrial use of metal-organic framework: Impact of shaping on the MOF properties

Abstract : Metal Organic Frameworks (MOF) or coordination polymers are porous crystalline materials made up of metal ions and organic ligands that emerged in the 1980s. While their synthesis is well documented, their shaping and formulation are rarely studied in the literature although this step conditions their proper assessment and their potential use in catalysis and separation at an industrial scale. This question is crucial as the properties of these materials require the development of new ways of shaping appropriate to their limited resistance, especially towards heat treatments. This work proposes, for a few representative MOF (ZIF-8, HKUST-1 and SIM-1), to assess the feasibility and impact of their shaping by compression - process most often mentioned in literature - on their structural, textural and catalytic properties. The textural characterization indicates a significant effect of compression on the microporosity of these solids. These changes can be considered as irreversible as shown by X-ray diffraction analysis indicating a loss of crystallinity proportional to the applied force. In the case of HKUST-1, the changes induced by compression are prohibitive. The ZIF-8 has been further studied because it could be a good candidate to industrial applications in catalysis: indeed, it undergoes moderate modifications under compression and it is known as a good catalyst in the transesterification reaction of vegetable oils. To this end, resistant pellets were obtained by adding an organic binder (cellulose ester, K15M) and pelletizing at different pressures. The effect on textural and structural changes induced by this shaping does not seem to be accompanied by modification of the acid-base properties of ZIF-8, which maintains a similar catalytic activity. The acid-base sites of this catalyst were characterized by infrared spectroscopy with adsorption of CO as a probe molecule. This analysis revealed that ZIF-8 acid-base sites are not altered by compression. This result is in good agreement with the stability of catalytic activity experimentally observed. It is noteworthy that, while the microporous surface area of the catalyst is reduced, its catalytic activity remains constant. This observation is consistent with the hypothesis of an external surface reactivity of ZIF-8.
Type de document :
Article dans une revue
Powder Technology, Elsevier, 2014, 255 (SI), pp.52-59. 〈10.1016/j.powtec.2013.09.013〉
Domaine :
Liste complète des métadonnées

https://hal.univ-lorraine.fr/hal-01275927
Contributeur : Lrgp Ul <>
Soumis le : jeudi 18 février 2016 - 14:59:47
Dernière modification le : mardi 15 mai 2018 - 14:50:03

Identifiants

Collections

Citation

Delphine Bazer-Bachi, L. Assie, Vincent Lecocq, Bogdan Harbuzaru, Véronique Falk. Towards industrial use of metal-organic framework: Impact of shaping on the MOF properties. Powder Technology, Elsevier, 2014, 255 (SI), pp.52-59. 〈10.1016/j.powtec.2013.09.013〉. 〈hal-01275927〉

Partager

Métriques

Consultations de la notice

146