CMK-1 nanostructured carbon replica modified with Zinc for Hydrogen storage

J.M. JUÁREZ; M.B. GÓMEZ COSTA; O.A. ANUNZIATA

Xiamen

Congreso; 3rd International Colloids Conference - Colloids and Energy; 2013

Elsevier

Ordered nanoporous carbon CMK-1 was synthesized via two step impregnation of the siliceous mesopores MCM-48, with a solution of sucrose using an incipient wetness method. The sucrose-silica composite was then heated at 1173 K for 4 h under nitrogen flow. The silica template was dissolved with 5 wt% hydrofluoric acid in order to remove the silica. The template-free carbon product obtained was filtered, washed with deionized water and ethanol, and dried.Zn-CMK-1 was prepared by wet impregnation using Zn (NO3)2.6H2O as source of Zn. In order to increase the amount of hydrogen adsorbed the sample of Zn-CMK-1 was treated under H2 flow, at 1173 K (H2-Zn-CMK-1).Porous carbon CMK-1 and the samples modified with Zn were characterized by XRD, FTIR, XPS, BET and SEM. These studies indicate that it was possible to obtain a CMK-1 replica successfully from MCM-48, using sucrose as a carbon precursor.In the XRD pattern of CMK-1 (10º-60º 2Theta), we observed two diffraction planes (0 0 2) and (1 0 0) that are typical of graphite. Moreover, in the XRD pattern of Zn-CMK-1 we observed ZnO characteristic peaks corresponding to the (100), (002), (101), (102), (110), (103), (200), (112) and (201) hkl index. These signals indicated that ZnO particles possessed polycrystalline hexagonal wurtzite structure.The surface areas are 1089 m2/g, 704 m2/g and 568 m2/g for CMK-1, Zn-CMK-1 and H2-CMK-1, respectively. While the nanomaterial area is significantly smaller with the incorporation of the metal, CMK-1`s characteristic structure is maintained after the metal is within the host, in agreement with the XRD studies.Measurements of hydrogen adsorption at cryogenic temperatures and low pressures were performed. Zn-CMK-1 had a lower hydrogen storage capacity than the carbon nanostructured CMK-1. While the sample that was thermally treated under hydrogen flow showed a greater H2 adsorption than the CMK-1 sample.