The structure and properties of two new UiO-67-type metal-organic frameworks, along with their linker synthesis and powder and single crystal synthesis, are presented. The new MOFs, UiO-67-Me and UiO-67-BN, are based on 3,3'-dimethylbiphenyl and 1,1'-binaphthyl linker scaffolds, and show a much higher stability to water than the thoroughly investigated UiO-67, which is based on the biphenyl scaffold. On the basis of structure models obtained from single crystal X-ray diffraction, it is seen that these linkers are partly shielding the Zr cluster. The new materials have higher density than UiO-67, but show a higher volumetric adsorption capacity for methane. UiO-67-BN exhibits excellent reversible water sorption properties, and enhanced stability to aqueous solutions over a wide pH range; it is to the best of our knowledge the most stable Zr-MOF that is isostructural to UiO-67 in aqueous solutions.

CO 2 hydrogenation was carried out over Pt-containing UiO-67 Zr-MOFs at T = 220−280 °C and ambient pressure, with H 2 / CO 2 = 0.2−9 and contact times, τ = 0.004−0.01 g cat •min•mL −1 . The catalysts were characterized by XRD, N 2 adsorption, FESEM, TEM and HRTEM, Pt L 3 -edge XANES and EXAFS, dissolution-NMR, CO chemisorption, IR spectroscopy, and TGA. A positive correlation was observed between the degree of Pt reduction and CO 2 conversion. Contact time variation experiments showed that CO is a primary product of reaction, while CH 4 is a secondary product. Testing of catalyst crystals with 0.15 and 2.0 μm crystal size, respectively, revealed no influence of diffusion on the reaction rate. Comparison to a conventional Pt/SiO 2 catalyst showed very similar activation energy, with E app = 50 ± 3 kJ• mol −1 . However, the turnover frequency over Pt/SiO 2 was significantly lower, and Pt/SiO 2 did not yield methane as a product. The Pt-containing UiO-67 Zr-MOF catalyst showed stable activity during 60 h of testing.

NMR crystallography of the fluorinated aluminophosphate cloverite is presented, with an emphasis on the description of the nonperiodic part of the compound, i.e., the fluorine and organic subnetworks, which are very difficult to access by usual X-ray powder diffraction methods. Multinuclear high-resolution 1D 27 Al and 31 P NMR support the main cloverite-type topological features previously proposed for aluminum cloverite from powder X-ray diffraction. Spatial proximities are extracted from the 2D 31 PÀ 31 P and 27 AlÀ 31 P NMR spectra, allowing a full assignment of the 31 P and 27 Al resonances to the corresponding phosphorus and aluminum sites in the structure. To go further into the description of the main periodic framework, 13 C, 15 N, and 1 H 1D and 1 HÀ 1 H and 1 HÀ 31 P 2D NMR measurements are employed, allowing the characterization and selective locations of the two costructural-directing agents in the pores and channels of the framework. The nonperiodic fluorine subnetwork is described by means of 19 F-X (X = 27 Al and 31 P) 2D NMR experiments. Two kinds of fluorine atoms are distinguished: F À ions trapped in D4R units and F atoms covalently bonded to terminal Al or P atoms and which interrupt the AlPO network. Through the example of aluminum cloverite, we show that, despite the considerable complexity of such systems, an extremely detailed structural model can be obtained, including the simple rules that allow the description of the nonperiodic subnetworks that tailor the structure and properties of a compound, by coupling powder X-ray diffraction and high-resolution NMR data in a generalized crystallography approach.