Preparation of Metal Organic Framework (MOF) Derived Bimetallic Catalyst for Dry Reforming of Methane

Abstract

In the past decade, efforts have been focused on development of catalyst to show high activity for dry reforming of methane (DRM). The development of catalyst has been crucial to be carried out as this may significantly reduce the concentration of most common greenhouse gases, namely methane (CH4) and carbon dioxide (CO2) in the atmosphere. In present work, a series of varying molar ratio of Ni:Ce metal organic framework (MOF) derived catalysts were grown on alumina in one step. The synthesis steps were in accordance to reported solvothermal method for the syntheses of NH2-MIL-88B with slight modification. This was followed by reduction at 500°C in hydrogen environment for 1 h. The physical and chemical properties of the catalysts were probed by powder XRD, BET surface area analysis, EDX, ICP, CO2-TPD and H2-TPR. XRD showed that diffraction patterns were in agreement with the diffraction pattern of MOF synthesized in previous work, thus confirmed the successful formation of the MOF structure. The variation in the molar ratio of Ni:Ce did not show significant difference in the diffraction pattern of the MOF-derived catalysts. For reduction phase, sharp diffraction peaks were detected at 2? = 44.5°, 51.85°, and 76.37°, which can be indexed to (1 1 1), (2 0 0) and (2 2 0) planes of face-centered cubic (FCC) metallic Ni, respectively. The addition of Ce promoted smaller particle size of Ni, ranging from 4.6 nm to 6.88 nm. The presence of CeO2 was observed at 2? = 28.6°, 33.0°, and 56.4°. Elemental distribution was compared between EDX and ICP-OES. ICP-OES and EDX analyses indicated that weight percent of bimetallic metal of Ni and Ce was consistent, in which the amount of respective metal obeyed the ratio trend of the metal precursors added during the MOF synthesis. This suggested the homogeneity of the catalyst, even though EDX showed relatively higher weight percent than ICP-OES. The catalytic performance of catalysts showed that 1Ni1Ce exhibited better conversion of CH4 and CO2, with 63.5% and 86.8% respectively at 800oC, and the conversion tend to increase at a higher temperature. The results were convincing for the design of a performing catalyst for DRM process.

Keywords

• alumina support
• dry reforming of methane
• metal organic framework
• nickel-cerium