Catalytic Features of Mg Modified Ni/SiO2/Silica Cloth Systems in the Decomposition of Methane for Making “CO x -Free” H2

Abstract

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 xfree'' 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.