Use of structured systems as a strategy to minimize the deactivation of Ni-based catalysts applied in dry reforming of methane

Abstract

Abstract The main challenge in the use of Ni based catalysts is the high deactivation rate of these catalysts. In this work, strategies aimed at improving this characteristic such as the use of structured catalysts were studied. In this work, the Ni/γ-Al2O3 (Ni/Al) and Ni/La2O3-γ-Al2O3 (Ni/La-Al) catalysts were synthesized by the all-in-one method and used in the Dry Reforming of Methane combined with its application in structured systems to minimize the effects of deactivation. The catalysts were characterized and a smaller Ni crystallite size for the La-promoted catalyst was observed. The deactivation of the structured catalysts and application of residual activity deactivation models (DMRA) were evaluated by applying different weight hourly velocities (WHSV). Besides that, the regeneration of the catalysts was developed through the comparison of the treatment with CO2 and H2 atmospheres. Furthermore, the greatest and the lowest deactivation of the structured systems were identified for the WHSV values of 40 and 20 L gcat−1 h− 1, respectively. Finally, the regeneration treatment with CO2 showed to be more efficient than the treatment with H2. A deactivation model was predicted in the region of equilibrium in the catalytic activity, which is associated with the appearance of a residual activity, which decreases with increasing WHSV variable.