Disclosing the Properties of a New Ce(III)-Based MOF: Ce₂(NDC)₃(DMF)₂

Abstract

The new Ce(III) based metal-organic framework Ce 2 (NDC) 3 (DMF) 2 , containing the simple ditopic linker napthalenedicarboxylate (NDC 2-), has been synthesized under solvothermal reaction conditions with high purity and yield. Its crystal structure was determined with SC-XRD techniques and further confirmed by Ce K-edge XAS. Upon thermal activation the compound revealed a phase transformation at about 300°C involving the removal of the solvent molecules which has been investigated in detail by TGA, VT-PXRD and FTIR spectroscopy techniques. The crystal structure of the compound after desolvation (Ce 2 (NDC) 3) becomes severely disordered, but a synergic use of both SC-XRD and Ce K-edge EXAFS allowed us to reveal its crystal structure. Porosity and adsorption properties were studied by the means of volumetric adsorption measurements. Ce2(NDC)3 is porous towards carbon dioxide at-78°C, resulting in a surface area of about 200 m 2 /g,. CO 2 uptake at 1 bar and 25°C is about 4% by weight.

Adsorption Properties of Ce5(BDC)7.5(DMF)4 MOF

“…Ce-based MOFs have recently created interest in the scientific community. General features that can be drawn from looking at the current published literature are the following: (i) both Ce 3+ and Ce 4+ oxidation states can be used in the synthesis of MOFs [5][6][7][8][9]; (ii) synthetic conditions for Ce 3+ -containing MOFs tends to be harsher than Ce 4+ [5,6,10]; (iii) usually, Ce 4+ starting reagents may be reduced to Ce 3+ during the synthesis [11,12]; (iv) Ce 3+ materials more frequently have peculiar structures, while Ce 4+ tends to give rise to MOFs with the same structure as other 4+ cations (e.g., Zr 4+ or Hf 4+ ) [5][6][7]13,14]. Their thermal stability is generally lower than their Zr 4+ counterparts [7,8,14,15].…”

“…Their thermal stability is generally lower than their Zr 4+ counterparts [7,8,14,15]. As a possible application of Ce MOFs as redox catalysts, Smolders et al [8] reported the successful use of Ce 4+ -UiO-67 in the aerobic oxidation of benzylic alcohol to benzaldehyde mediated by TEMPO (2,2,6,. Furthermore, Ethiraj et al [5] reported the use of a Ce 3+ -based MOF for the selective capture and storage of CO 2 , obtaining high figures of merit of capacity and separation.…”

Uncovering the Structural Diversity of Y(III) Naphthalene-2,6-Dicarboxylate MOFs Through Coordination Modulation

“…Despite the ability to remove solvent molecules from the materials, none were found to be porous to N 2 at 77 K. Removal of coordinated DMF from 1 and 4 presumably results in framework collapse, although it is noted that during the peer review period, a Ce(III) analog of 1 was reported which could be desolvated at 300°C to a phase that was porous to CO 2 (Atzori et al, in press). For 5 , whilst the framework does show void space, it is possible that access to the void channels is blocked due to charge-balancing dimethylammonium ions lying in the cluster layer of the framework.…”

Metal–organic frameworks for carbon dioxide capture

“…90 A highly selective adsorption of CO 2 has been reported for the green CD-MOF-2 formed by the renewable cyclic oligosaccharide γ-cyclodextrin and RbOH, the reversible carbon fixation occurring through carbonate formation and decomposition at room temperature. 91…”