Effect of Rh Addition to Ni/MgO-Al 2 O 3 Catalysts for Dry Reforming of Methane

Abstract

Objective: This study has analyzed the performance of Ni and Ni-Rh catalysts based on MgO/g-Al2O3 in the process of dryreforming of methane (DRM). Methods/ Statistical Analysis: The samples were prepared using the incipient wetnessimpregnation method and were characterized by N2 adsorption, X-ray diffraction (XRD), temperature-programmedreduction (TPR), diffuse reflectance spectroscopy (DRS), surface acidity, X-ray photoelectron spectroscopy (XPS), thermalgravimetric analysis (TGA), and Raman spectroscopy. The catalysts were reduced with hydrogen and measured in thereaction of CH4 with CO2 at two CH4/CO2 ratios. Findings: The 0.5% Rh addition to Ni/MgO-g-Al2O3 improves the activityand the stability for this process. In the bimetallic catalysts, the reduction temperature of the active phase decreases dueto the hydrogen spillover mechanism from the noble metal to the catalyst surface, which favors their catalytic activity. Onthe other hand, the interaction between Rh and the support would be the cause for the better performance of bimetalliccatalysts. The Rh-Ni/MgO-g-Al2O3 catalyst is the most active, indicating that the impregnation order affects the catalyticbehavior. Improvements/Applications: This study gives promising results for this type of catalyst, also showing the effectof the catalyst preparation on the activity and its relationship with deactivation by coke.