The EDELWEISS experiment is a direct search for Weakly Interacting Massive Particles (WIMP) dark matter using an array of twenty-four 860 g cryogenic germanium detectors equipped with a full charge ...and thermal signal readout. The experiment is located in the ultra-low radioactivity environment of the Modane underground laboratory in the Frejus tunnel. WIMP limits, background rejection factors and measurements of cosmogenic activation recorded in long exposures are used to assess the performance of the third generation of EDELWEISS detectors in view of the search for WIMPs in the mass range from 1 to 20 GeV/c2. The developments in progress to pursue this goal in the coming years are also presented.
The future TESSERACT experiment will search for individual galactic DM particles below the proton mass through interactions with advanced, ultra-sensitive detectors. Currently TESSERACT is in a ...design phase aiming to produce fully defined detector technologies that will explore DM masses down to 10 MeV. It is designed to be sensitive to DM candidates interacting with the detector target material in producing both nuclear recoil DM (NRDM) and electron recoil (ERDM). To do so, multiple target materials will be used with varying detection strategies to ensure the capability to both actively reject the so-called low-energy excess and discriminate nuclear recoils against electron recoils. In addition to maximizing sensitivity to a variety of DM interactions, this provides an independent handle on instrumental backgrounds. Nowadays, the TESSERACT project encompasses two US-based technologies, namely HeRALD using superfluid helium as a target material, and SPICE using polar crystals (Al2O3 and SiO2) and scintillating crystals such as GaAs. In these proceedings, we discuss the recent proposal to host the future TESSERACT experiment at the Modane Underground Laboratory (LSM) and add a third French-based cryogenic semiconducting (Ge, Si) detector technology to the TESSERACT payload.
A heterogeneous molecular catalyst based on IrIIICp* (Cp*=pentamethylcyclopentadienyl) attached to a covalent triazine framework (CTF) is reported. It catalyses the production of hydrogen from formic ...acid with initial turnover frequencies (TOFs) up to 27 000 h−1 and turnover numbers (TONs) of more than one million in continuous operation. The CTF support, with a Brunauer–Emmett–Teller (BET) surface area of 1800 m2 g−1, was constructed from an optimal 2:1 ratio of biphenyl and pyridine carbonitrile building blocks. Biphenyl building blocks induce mesoporosity and, therefore, facilitate diffusion of reactants and products whereas free pyridinic sites activate formic acid towards β‐hydride elimination at the metal, rendering unprecedented rates in hydrogen production. The catalyst is air stable, produces CO‐free hydrogen, and is fully recyclable. Hydrogen production rates of more than 60 mol L−1 h−1 were obtained at high catalyst loadings of 16 wt % Ir, making it attractive towards process intensification.
H2 and triazine frameworks: The synthesis, characterization, and catalytic performance of a new heterogeneous molecular catalyst based on IrIIICp* (Cp*=pentamethylcyclopentadienyl) attached to a covalent triazine framework is reported. It catalyses the selective production of hydrogen from formic acid with very high initial turnover frequencies and turnover numbers in continuous operation. The catalyst is air stable, produces CO‐free hydrogen and is fully recyclable.
Metal-organic frameworks (MOFs) with non-coordinated amino groups, i.e. IRMOF-3 and amino-functionalized MIL-53, are stable solid basic catalysts in the Knoevenagel condensation of ethyl cyanoacetate ...and ethyl acetoacetate with benzaldehyde. IRMOF-3
DEF exhibits activities that are at least as high as the most active solid basic catalysts reported, with a 100% selectivity to the condensation product. For IRMOF-3 samples the catalytic activity correlated with the accessibility of the basic sites. Diffusion limitations could be excluded for this most active catalyst. A new MOF based on the MIL-53 topology and non-coordinated amino groups has been synthesized and characterized. Although active its poor performance in the studied Knoevenagel condensations is attributed to strong adsorption and diffusion limitations in the 1-D pore structure of this framework. The performance of the IRMOF-3 catalysts demonstrates that the basicity of the aniline-like amino group is enhanced when incorporated inside the MOF structure, increasing the
p
K
a
of the basic catalyst and more active than aniline as homogeneous catalyst. The IRMOF-3 catalysts are stable under the studied reaction conditions, and could be reused without significant loss in activity. The catalytic performance of IRMOF-3 in various solvents suggests that this open, accessible and well-defined structure behaves more like homogeneous basic catalysts, in contrast to other solid basic catalysts. By means of DRIFTS, the reaction mechanism has been elucidated, showing spectroscopic evidence of benzaldimine intermediates.
Metal organic frameworks (MOFs) with non-coordinated amino groups are shown to be stable solid basic catalysts. The performance of the IRMOF-3 catalysts demonstrates that the basicity of the aniline-like amino group is enhanced when incorporated inside the MOF structure.
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