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

In this work, the Ni/gamma-Al2O3 (Ni/Al) and Ni/La2O3-gamma-Al2O3 (Ni/La-Al) catalysts were synthesized using the all-in-one method and applied to dry methane reforming, with the aim of minimizing the effects of deactivation through the use of La and the application of monoliths. The characterization showed a smaller Ni crystallite size for the catalyst promoted by La, which was associated with better dispersion of its active phase. The monoliths showed a conversion rate around 15% higher than that of the powdered catalysts. By studying the deactivation of the monoliths and applying residual activity deactivation models (DMRA), it was possible to verify a fit with R-2 greater than 0.90 and RMSE values below 5%, with the model predicted and adjusted to the residual activity region. In addition, the highest and lowest deactivation of the structured systems was identified for WHSV values of 40 and 20 L h(-1) g(-1)cat, respectively. Finally, the regeneration of the catalysts with CO2 proved to be superior to that with H-2, with a regeneration rate of 90% in the first two cycles.

Automated summary

In this study, Ni/gamma-Al2O3 (Ni/Al) and Ni/La2O3-gamma-Al2O3 (Ni/La-Al) catalysts were synthesized using the all-in-one method and applied to dry methane reforming. The results showed that the Ni crystallite size was smaller for the catalyst promoted by La, indicating better dispersion of its active phase. The monoliths exhibited a higher conversion rate compared to the powdered catalysts. Deactivation of the monoliths was studied using residual activity deactivation models (DMRA) and a good fit was achieved with high accuracy. The deactivation level of the structured systems was found to vary with the WHSV values. Finally, CO2 regeneration showed superior results compared to H-2 regeneration for the catalysts.