Conclusions
In this work, we have employed a flexible Mn-bpdc MOF featuring distinct
gate-opening and reversible switch behavior for
C4H6 purification. The intrinsic
flexibility is confirmed by VT-XRD with gradient temperature control. In
addition, the different polarity guest-depended molecule can lead to
structure transformation with different gate-opening pressure points at
different temperatures, such as C2H4 and
C3H6. Importantly, it exhibits prominent
gate-opening and abrupt adsorption for
C4H6 at very low pressure (0.13 bar) but
no stimulus-response behavior for all
n-C4H8,iso-C4H8,
n-C4H10 and
iso-C4H10 even at 1 bar and ambient
conditions. Notably, the uptake selectivities of Mn-bpdc MOF for both
C4H6/n-C4H8and
C4H6/iso-C4H8surpass whole the reported adsorbents. Furtherly, four dynamic
breakthrough experiment results of
C4H6/n-C4H8,
C4H6/iso-C4H8,
C4H6/n-C4H10and
C4H6/iso-C4H10mixtures verifies that this Mn-bpdc MOF can practically separate
C4H6 from other C4paraffins and mono-olefins. In addition, the unexpected water stability,
benign regeneration ability, signifies that this MOF has great
potentiality
for industrial C4H6 purification and
makes it a new benchmark of
flexible adsorbent for the separation of
C4H6 over other C4hydrocarbons.