Ni-Silica-based Catalysts for CH4 Reforming by CO2 with Enhanced Stability: Recent Designs and the Impacts of Ni Confinement, Promoters, and Core-Shell Structures

CO2 reforming of CH4, also referred to as the Dry Reforming of Methane (DRM), is considered an excellent method to produce H2 and CO (syngas), which are known to be used for the production of higher alkanes and oxygenates. Despite nickel’s moderate toxicity, Ni-based heterogeneous catalysts are considered excellent candidates for use in DRM due to their reasonable performances and economic advantages. However, these materials also present severe drawbacks, such as sintering of the active phase and coke (carbon) deposition, which may, in certain cases, lead to severe catalyst deactivation. Several synthesis strategies, mostly based on the stabilization of nickel through oxide support, have been developed to overcome these issues. Silica-based materials are investigated widely due to their availability, high surface area, and the confinement capacity conferred by their controlled porosity. The present review summarizes the progress in the design of Ni/silica-based catalysts for the dry reforming of methane between the years 2015 and 2018. The different strategies implemented are discussed to assist future research works in designing the anti-coking and anti-sintering nickel-silica-based catalysts.