The influence of nickel particle size in the range of 1.6-7.3 nm on catalyst performance in low temperature CO2 reforming of methane reaction has been investigated using well-defined catalysts based on a neutral silica support. XAS and XPS studies indicated a reduction degree greater than 90%. The intrinsic Ni/SiO2 performances were found to be independent of nickel particle size in dry reforming at 773 K using a CH4/CO2 ratio of 1.3 at 1 atm, both at an early stage and in steady state conditions. The H-2/CO ratio was also found to be structure in sensitive but is controlled by thermodynamics through the faster reverse water gas shift reaction. (c) 2012 Elsevier Inc. All rights reserved.