Mechanistic Study of Porosity Formation in Liquid-Assisted Mechanochemical Synthesis of Metal-Organic Framework Cu3(BTC)2 for Adsorption-Based Applications

Abstract

The mechanochemical synthesis of metal-organic framework Cu3(BTC)2 was conducted with various amounts of water–ethanol liquid added prior to grinding. Using the XRD, SEM and N2 sorption results, an attempt was made to explain the mechanisms by which liquid may affect the formation of Cu3(BTC)2 and its porosity in the grinding process. The experimental results show that microporosity is controlled by the degree of crystallinity of Cu3(BTC)2 structures. Within the range of liquid-assisted grinding (LAG), it is found that an increase in the amount of liquid in grinding leads to a larger microporosity in Cu3(BTC)2. The formation of mesoporosity and macroporosity is determined by two competing events in LAG: particle breakage and its agglomeration. When the addition of liquid leads to particle breakage over its agglomeration as the dominant event in LAG, it results in smaller Cu3(BTC)2 particles, and the network space of these particles constitutes mesoporosity and macroporosity. When the addition of liquid gives rise to particle agglomeration as the dominant event, however, most of this network space collapses so that mesoporosity and macroporosity in the Cu3(BTC)2 samples diminish significantly.

Mechanochemical synthesis and application of mixed-metal copper–ruthenium HKUST-1 metal–organic frameworks in the electrocatalytic oxygen evolution reaction

“…23 The liquid medium in LAG and iLAG assists in the deprotonation of the linkers stabilizes intermediates and the pores of the MOF. 24,25 It has been reported that mechanochemical synthesis of MOFs can greatly reduce reaction times from several hours or days to 15 min. 26 In addition, a mechanochemical experiment by Gao et al found that up to 20 g of the MOF Zn-atz-ipa could be produced in a single batch in just 20 min.…”