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Chapter 4 121<br />
DEMOFs. Moreover, as the generation of only defect type B was observed in Ru-DEMOF<br />
analogs of HKUST-1 with ip DL, the effect from different metal ions (Cu, Ru) on the<br />
formation of intentional defects in M-DEMOFs should also be taken into account.<br />
4.3.4 Conclusions<br />
Adopting Cu(NO3)2∙3H2O and Cu(BF4)2∙6H2O as metal sources and different feeding of<br />
H2ip DL results in crystalline Cu-DEMOFs, which are isostructural analogs of Cu-BTC. All<br />
obtained Cu-DEMOF solids show good thermal stability, which appeared to be not affected<br />
by the employed reactants (i.e. metal salts and solvents). Based on the composition and<br />
porosity, DMF found to be a better reaction solvent than EtOH leading to higher<br />
incorporation degree of ip and higher porosity of the resulting DEMOFs (for the given<br />
feeding). However, when the feeding of ip is increased, the usage of Cu(NO3)2∙3H2O as<br />
precursor should be carefully monitored owing to accompanied effects of guest(s)<br />
inclusion. Nevertheless, current studies demonstrate the highest ip framework<br />
incorporation into Cu-BTC could reach up to 25%.<br />
More importantly, UHV-IR spectra recorded upon CO dosing suggest generation of Cu + in<br />
the prepared Cu-DEMOF samples D1 and D2. Two important caused factors are<br />
concluded: one is related with the intrinsic defects induced by thermal activation and the<br />
other is intentional defects (i.e. modified PWs). In the case of intentional defects, usage of<br />
reducing agents, modifying the metal precursors including the cations and anions could<br />
be the driven force to generate reduced metal-sites. In one word, even in the “simple<br />
looking” HKUST-1 (in comparison with its Ru analogs), the defect-engineering is<br />
complicated and carefully consideration is required for the elaboration.
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