(370g) Molybdenum Based-Catalysts for the Reforming of Liquid Hydrocarbons for Fuel Cell Applications
In the present study, we have studied the performance of molybdenum-based catalysts for the production of H2 to power solid oxide fuel cells (SOFCs). In previous work, molybdenum dioxide (MoO2) was found to exhibit high activity as well as coking resistance and sulfur tolerance during the reforming of liquid fuels such as jet fuel and gasoline. On the other hand, molybdenum carbide (Mo2C) has been previously reported as highly active for the reforming of methane. However, the use of Mo2C for the partial oxidation of higher hydrocarbons has not been reported in the literature. To overcome this lack of information, we have investigated the performance of molybdenum carbide (Mo2C) as potential catalyst for the reforming of liquid hydrocarbons via partial oxidation. Our results indicate that at 850°C, 1 atm and a stoichiometric oxygen to carbon molar ratio, the use of MoO2 leads to a higher production of syngas as compared to that obtained when using commercial Mo2C. However, stability issues prevent the use of MoO2 for long periods of time. This problem seems to be related to the formation of hot spots in the catalyst bed that may deteriorate the crystalline structure and, hence, the oxygen mobility that is crucial to maintain the catalytic activity of this transition metal oxide. Different approaches are discussed to increase the stability of the oxide phase such as doping and the use of supporting materials. Our recent findings indicates that the doping of MoO2 with titanium enhances the stability of this oxide whereas supporting MoO2 on silicon dioxide (SiO2) leads to the formation of MoO2 nanoclusters with high resilience to sintering.