Shaping metal–organic framework (MOF) powder materials for CO2 capture applications—a thermogravimetric study

Abstract

The paper presents the effect of the tabletting pressure and time on the chemical structure and crystallinity of the CuBTC and MIL-53(Al) metal-organic framework tablets. For MOFs, the no-binder tabletting method was employed using a pressure of 3.7, 7.4, 29.6 and 59.2 kN m-2 , respectively, for a duration of 0.5, 1 and 2 min. The obtained tablets were crushed and sieved to obtain the desired fraction from 500 to 650 lm. In this study, the thermogravimetric test has been used for the assessment of the effect of shaping metal-organic frameworks on the CO 2 adsorption properties. The examination of the CO 2 sorption capacity of metal-organic frameworks was carried out using a Mettler TGA/SDTA 851e thermobalance and TG-Vacuum. The results indicate a significant effect of compression on the crystal structure and CO 2 sorption capacity of MOFs.

From metal–organic framework powders to shaped solids: recent developments and challenges

“…There is, however, a small shift of the reflections towards larger 2 values. The authors attributed this phenomenon to structural deformations of the framework upon compression, in accordance with the results provided by Majchrzak-Kuceba and Sciubidlo [36]. In addition, it was shown that textural properties were altered accordingly.…”

Recent advances in process engineering and upcoming applications of metal–organic frameworks

“…Before S. A. After Process time Ref Binder-free MOF-5 – 2750 2600 ~ 1200 – [166] CPO-27-Ni – 1060 1050 30 min [167] CuBTC (Basolite™ C300) – – – – [168] MIL-53(Al) – – – – [168] HKUST-1 – – – 3 h [169] UiO-66 – 1175 511 / 417 6–18 h [155] HKUST-1 – – – 11 h [170] ZIF-8HT – – 1387 1 d [170] ZIF-8LT – – 1359 1 d [171] ZIF-8LT-HT – – 1423 1 d [171] ZIF-8ER – – 1395 1 d [171] …”

Structure Effects Induced by High Mechanical Compaction of STAM‐17‐OEt MOF Powders

“…This last aspect is not at all trivial, because in literature many MOFs have been subjected to densification processes with or without the help of chemical binders, but in most cases a significant loss of crystallinity and surface area have been found, compromising the typical performances of the material, especially as adsorbent or catalyst. [4,[11][12][13][14][15][16][17][18][19][20][21] Recently, after many unsuccessful attempts, [4,[11][12][13] it has been found that HKUST-1 (or Cu-BTC), which is considered a reference system for all of the copper paddle wheel MOFs like STAM-17-OEt, is actually very easy to compact if the appropriate protocol is applied. [22] However, HKUST-1 is very sensitive to water and it typically undergoes severe hydrolysis even by limited exposure to air.…”

“…Surprisingly, the new MOF STAM‐17‐OEt (Cu(C 10 O 5 H 8 ) ⋅ 1.6 H 2 O) combines all these extraordinary properties: it is flexible (or better, hemilabile), [7–9] extremely water‐stable, [7,8,10] and with this work we show that it is also very resistant to the mechanical pressures necessary for the industrialization of the material, and therefore easy to densify and commercialize even if originally synthesized in powder form. This last aspect is not at all trivial, because in literature many MOFs have been subjected to densification processes with or without the help of chemical binders, but in most cases a significant loss of crystallinity and surface area have been found, compromising the typical performances of the material, especially as adsorbent or catalyst [4,11–21] . Recently, after many unsuccessful attempts, [4,11–13] it has been found that HKUST‐1 (or Cu‐BTC), which is considered a reference system for all of the copper paddle wheel MOFs like STAM‐17‐OEt, is actually very easy to compact if the appropriate protocol is applied [22] .…”