Synthesis and characterization of CMK-1 modified with Ni and Zn nanoparticles for efficient Hydrogen storage

JULIANA M. JUÁREZ; MARCOS B. GÓMEZ COSTA; OSCAR A. ANUNZIATA

Estambul

Congreso; 4th international advances in applied physics and materials science congress ? APMAS 2014; 2014

Doga Nano Biotech

We have shown that a promising hydrogen storage material can be obtained by ordered porous carbon CMK-1 modified with Ni and Zn, which was synthesized by replication using MCM-48 as template and incorporation of metals, was carried out by wetness impregnation considering the effects of thermal reduction treatment. The CMK-1 modified with Zn and treated with H2 at 1173 K present a better capacity for hydrogen uptake than the nanometric CMK-1 and Ni-CMK-1. The samples were characterized by XRD, FTIR, SEM, TEM, XPS and BET methods. The CMK-1 modified with Zn showed the highest H2 uptake at low and high pressures (4.4wt% of H2 sorption at 10 bar and 77 K). The introduction of Ni into CMK-1 does not increase the hydrogen storage capacity at low pressure. However, at higher pressure Ni-CMK-1 results in the hydrogen uptake larger than that of the Ni-free CMK-1 (2.4 and 2.1 wt% respectively). The nanoparticles of Zn have a smaller size than nanoparticles of Ni, consequently the metal dispersion is higher and the occlusion of nanopores of the carbon framework is low, with better hydrogen adsorption of the Zn-CMK-1. However the Ni-CMK-1 adsorbs more amount of hydrogen than carbon at high pressures due to the interactions H2/metal or H2 /metal-oxide become more evident. A hydrogen storage mechanism on metal/carbon surfaces was proposed. We can conclude this work indicating that CMK-1 hydrogen storage capacity was increase by addition of metal clusters, controlling the metal cluster size and dispersion and also increasing the carbon specific surface area.