Partial Oxidation of Methane over CeO2 Loaded Hydrotalcite (MgNiAl) Catalyst for the Production of Hydrogen Rich Syngas (H2, CO) /

Abstract

Syngas production from CH4 is the most economical route for CH4 effective utilization. Partial oxidation of methane (POM) is one of the best methane activation process for syngas production. Catalytic materials employed in POM requires a better catalytic performance in terms of activity and stability to make this process commercially applicable. Hydrotalcites, owing to their strong basic properties and uniform distribution of metallic particles inside their structure are suitable for POM applications. CeO2 with strong redox properties due to its high oxygen storage capacity is an effective promoter for POM reaction. In this work, partial oxidation of methane (POM) was investigated using Mg-Ni-Al (MNA) hydrotalcite promoted CeO2 catalyst in a fixed bed reactor. MNA hydrotalcite was synthesized using the co-precipitation process, while CeO2 was incorporated via the wetness impregnation technique. The CeO2@MNA samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Xray analysis (EDS), thermal

gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) technique. The catalytic activity of CeO2 promoted MNA (CeO2@MNA) for POM reaction was evaluated for various CeO2 loading kept the feed ratio CH4/O2=2 at 850 °C. The catalyst containing 10 wt.% cerium loading (10%CeO2@MNA) showed 94% CH4 conversion with H2/CO ratio above 2.0, that is more suitable for FT synthesis. The performance of catalyst is attributed to highly crystalline stable CeO2@MNA with better Ce-MNA interactions withstand for 35 h time on stream. Furthermore, the spent catalyst was examined by TGA, SEM-EDS, and XRD to evaluate the carbon formation and structural changes during the span of reaction time.