Catalytic features of Mg modified Ni/SiO2/silica cloth systems in the decomposition of methane for making "COx-free" H2

The influence of the Mg addition on the catalytic performance of a 20% Ni based SiO(2)/silica cloth system in the decomposition of methane for making "CO(x)-free" H(2) in the T(R) range 773-873 K has been evaluated. As the Mg(at)/Ni(at) ratio increases from 0.10 to 2.20 the incipient Ni-Mg-O interaction becomes stronger until the formation of Ni(x) Mg((1-x))O solid solution. The presence of Mg(2+) ions allows a higher carbon capacity (C/Ni, number of CH(4) molecules converted per Ni atom until complete catalyst deactivation) and consequently a higher H(2) productivity of the Ni based systems which results in a smoothing effect of the unavoidable declining activity trend even if it does not affect the tip growth coking mechanism.