Nanostructured Carbon Material Modified with Titania Applied in Hydrogen Uptake and Storage.

JULIANA JUAREZ; BRENDA C. LEDESMA; MARCOS GOMEZ COSTA; ANDREA BELTRAMONE; ANUNZIATA OSCAR

Congreso; European advanced materials congress; 2017

This work deals with a development of a novel procedure to synthetized nanostructured carbon modified with highly dispersed titania in the anatase phase, employing Ti-SBA-15 as hard template. Ti-SBA-15 was synthesized using Tetraethylorthosilicate (TEOS, 98%, Sigma?Aldrich), Tetraethylorthotitanate (TEOT, 98% Sigma?Aldrich), Pluronic 123 in acidic medium. The mesoporous carbon Ti-CMK-3 was synthesized using the nanocasting strategy, via a twostep impregnation of the mesopores of Ti-SBA-15 (Si/Ti= 20) with a solution of sucrose as source of carbon using an incipient wetness method. The titania incorporated in the mesoporous carbon is in the anatase phase according to XRD, XPS and Uv-Vis analyses. The new mesoporous carbon displays a high specific surface area of 1044 m2/g, a large pore volume of 0.7 cm3/g. In the case of the novel Ti-CMK-3, the XRD pattern shows the same peaks as those of CMK-3, suggesting that the ordered structure of this material is similar to that of CMK-3 without Ti. However, it shows a slight shift to higher angles with a decrease in the unit cell parameter (ao). A shift to higher values can/may mean that the material has a better structural order. Two other factors that contribute to peak shift and wider signal comprise residual stress and defects in the material, since they can also deform the lattice. The wide angle XRD pattern of Ti-CMK-3 indicate that ordered structure of this material is similar to the CMK-3. XPS and UV-Vis analysis indicated that Ti is as anatase phase in Ti-CMK-3. To verify the composition of Ti-CMK-3 sample, energy-dispersive X-ray spectroscopic (EDX) characterization and elemental mapping of our material were carried out, showing a detailed evidence about C, Ti and O distribution of TiCMK-3 matrix. From EDX measure and elemental mapping, uniform distribution of Ti atoms was confirmed. By Map Sum Spectrum, the elemental composition of Ti-CMK-3 indicate that Ti is implanted in C framework of CMK-3 as anatase phase. The ability of hydrogen storage was measured at different pressures and cryogenic temperatures (77 K). The synthesized Ti-CMK-3 exhibited significantly enhanced H2 storage properties (2.6 wt.%) compared with CMK-3 without Ti (2.2 wt.%) at 77K and 10 bar.