Synthesis and Analysis of Molybdenum and Iron Catalysts for Non-Oxidative Methane Coupling

Methane coupling is a method for producing light hydrocarbons such as ethylene, offering an alternative to oil-based processes, which can contribute to a global reduction in fossil fuel usage. Most methane is burned to create energy because it is difficult to convert methane to other molecules efficiently. Methane is a greenhouse gas that once it reaches the atmosphere contributes greatly to global warming. This study focuses on using molybdenum (Mo) and iron (Fe) catalysts to facilitate non-oxidative methane coupling. Non-oxidative methane coupling is a desirable process because it does not produce carbon monoxide as an unwanted byproduct. The monometallic Mo and bimetallic MoFe catalysts with varied Fe loading were prepared by incipient wetness impregnation. After calcination, the catalysts were evaluated for catalytic performance in a fixed-bed reactor. Prior to the reactions, the catalysts were treated with methane and hydrogen while heating to the desired temperature, to obtain the desired active phase for the methane coupling. The reactions were run under various methane partial pressures and temperatures to study the reaction kinetics. The reactor was connected to a gas chromatography to quantify the output stream. Additional techniques such as chemisorption and X-ray diffraction were also employed to study the properties of these catalysts. From these experiments, we determine how the activation energy of the reaction influences the reaction, how different Fe loadings affect production, and how different methane concentrations impact the products. Future research involving the use of platinum bimetallic catalysts and different metal loadings could be done to further enhance the understanding of this reaction system. With a better understanding of the reaction and more efficient catalysts, methane could be converted into useful products in a more cost-effective manner. This will help encourage methane to be converted to useful chemicals which will decrease methane emissions and help decrease the issue of global warming.