Catalytic materials for Methane Dry Reforming reaction

Abstract

The process of simultaneous conversion of CH4 and CO2 to obtain syngas (CO and H2) is known as Dry Reforming of Methane (DRM). The reaction is strongly endothermic so it requires high temperatures, as well as an efficient catalytic system in terms of activity and stability. However, despite the latest advances, the reaction is not yet applied at industrial level due to easy deactivation of the catalytic systems, in particular the ones based on Ni. This because of two reasons: coke deposition, formed by secondary reactions and sinterization of active phase due to the high temperatures required. This thesis is focused on the development of a resistant catalytic system, evaluating two different approaches: the addition of promoters and a different catalytic structure. The first part of the research concerned about the development and testing of Ni/Al2O3 supported catalysts with the introduction of promoters such as Vanadium and Calcium in different wt.%. The second part of the thesis is focused on the synthesis and characterization of Ni@Al2O3 core-shell catalysts, a suitable and not so studied material for DRM purposes. The catalysts obtained are tested for the DRM reaction at 650°C in a fixed bed reactor with a GHSV of 12000 h-1, using different reagents ratios (CH4/CO2/He 1:1:18 and 2:2:16), under a total flow of 200 mL/min. The fresh and spent catalysts are characterized using various techniques including: XRD, SEM-EDX, TEM, TPR, TPO, TPD, N2 physisorption, CHNS analyses, DRS.