Peculiarities of high-pressure hydrogen adsorption on Pt catalyzed Cu-BTC metal-organic framework.

Hydrogen adsorption ability is a key parameter characterizing advanced porous materials. Herein, the influence of platinum catalyst on the interaction of Cu-BTC with hydrogen is thoroughly investigated using volumetric measurements, calorimetric titration, XRD, and IR- and EPR spectroscopy. The first hydrogen adsorption by the Cu-BTC + Pt/C composite leads to an irreversible chemical reaction related to the formation of structural defects during synthesis.

Luminescence in germania-silica fibers in a 1-2 μm region.

We analyze the origins of the luminescence in germania-silica fibers with high germanium concentration (about 30 mol.% GeO) in the region of 1-2 μm with a laser pump at the wavelength 532 nm. We show that such fibers demonstrate the high level of luminescence which unlikely allows the observation of photon triplets, generated in a third-order spontaneous parametric downconversion process in such fibers.