Development of stable bimetallic catalysts for carbon dioxide reforming of methane

Using a coprecipitation method to form Ni-Me-Al-Mg-O composite, Ni-Me (Me = Co, Fe, Cu, or Mn) bimetallic catalysts were prepared for carbon dioxide reforming of methane. Catalyst screening with the reforming reaction showed that Ni-Co bimetallic catalyst had superior performance in terms of activity and stability to other Ni-Me combinations. In a 2000 h stability test under the conditions of 750 degrees C, 1 atm, and GHSV of 110,000 mL/g(cat)-h (0.05 g of catalyst and 5.5 L/h gas flow rate), Ni-Co catalyst showed very stable performance with very low carbon formation. Reducing Ni and Co content from 6.1 and 9.3 to 3.6 and 4.9 mol% (metal base), respectively, rendered to completely eliminate carbon deposition for up to 250 h. Catalyst characterization was conducted using ICP-MS, BET, XRD, H-2-TPR, CO2-TPD, CO-chemisorption, TEM, and TG. It is believed that the synergy between Ni and Co can significantly improve catalyst performance and reduce carbon formation. A high metal dispersion or small ensemble size can be enhanced by reducing the Ni-Co content. The high activity and excellent stability of Ni-Co catalyst was closely related to its high metal dispersion, strong metal-support interaction, and formation of stable solid solutions. (C) 2007 Elsevier Inc. All rights reserved.