Recent advances in Ni-based stable catalysts for methane dry reforming: Stable catalysts' preparation review

This paper reports advances on the preparation of stable Ni-based catalysts for DRM reaction using various supports, promoters, synthesis methods, and pre-treatment temperatures through improvement of Ni dispersion and strength of metal-support interactions. Plasma-treatment, evaporation-induced self-assembly, ammonia evaporation, and homogeneous precipitation synthesis prepare very stable catalysts owing to high Ni dispersion and strong metal-support interactions, i.e., maximum H2TPR reduction T >= 600 degrees C. Ni particles are >= 2 times smaller than particles prepared using impregnation. The catalysts with maximum H-2-TPR reduction T < 600 degrees C exhibited rapid deactivation due to rapid Ni agglomeration and coking. Promoters improve Ni dispersion and occasionally, metal-support interactions as well while increasing pre-treatment temperature increases metalsupport interactions. However, there is contradictory effect on Ni particle size by pre-treatment. Alumina, silica, perovskites, and spinel materials interact strongly with Ni contrary to ZrO2 and MgO. Ni particles are also highly dispersed over high surface area supports e.g. silica, alumina, spinel materials which remarkably improves the stability. Significant progress has been made improving Ni dispersion, catalysts metal-support interactions and ultimate stability using various supports, synthesis methods, promoters, and pre-treatment temperatures.