Scalable synthesis and stability
In order to promote the industrialization of MOFs materials, it is the
general trend to produce stable MOF materials at low costs and with
simple operation processes. Therefore, a water-based and scalable
synthesis was developed at room temperature for the large-scale
preparation of
[Zn2(bpy)(btec)(H2O)2]·2H2O.39As shown in Figure 7a, only by mixing the metal salt and the ligands in
aqueous solution and stirring for 30 minutes, then filtering and drying,
can we obtain more than 320 g of product at room temperature. TGA and
DSC were tested on
[Zn2(bpy)(btec)(H2O)2]·2H2O
to explore its thermal stabilities (Figure 7b). Below 150 °C, the
initial weight loss of ~14% was accounted for by the
loss of water molecules, and then Zn2(bpy)(btec) can
stabilize up to about 410 °C before its decomposition.
Besides, the adsorbents require relatively high thermostability to keep
a long operation lifetime, The real
C2H2-relevant separation tasks are
typically implemented under more extreme conditions, typically
containing a trace amount of water and acidic gases.40Herein, the structural stability of Zn2(bpy)(btec) was
examined in detail. As depicted in Figure 7c, d, the PXRD patterns of
those materials treated under extreme conditions (acid, base, or boiling
water) coincide with those of pristine samples, which indicates that its
structure has no framework collapse and still retains its crystallinity.
After such treatment, its C2H2adsorption is largely maintained, comparable to the initial value
(Figure S11), which demonstrated that this material is highly stable in
the acidic/basic solutions (pH=1~13), even in the water
up to 120 °C. The water and thermal stability of
Zn2(bpy)(btec) has been superior to most
C2H2-separated MOFs (Figure 7e). Its
exceptionally high stability is due to its dense structure forming by
the strong multiple hydrogen bonding interactions and offset π-π
stacking interactions (Figure S12).