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 SiO2/silica cloth system in the decomposition of methane for making “COx-free” H2 in the TR range 773–873 K has been evaluated. As the Mgat/Niat ratio increases from 0.10 to 2.20 the incipient Ni–Mg-O interaction becomes stronger until the formation of NixMg(1−x)O solid solution. The presence of Mg2+ ions allows a higher carbon capacity (C/Ni, number of CH4 molecules converted per Ni atom until complete catalyst deactivation) and consequently a higher H2 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.